Improve mkuzip(8) and geom_uzip(4), merge in LZMA support from mkulzma(8)
and geom_uncompress(4):
1. mkuzip(8):
- Proper support for eliminating all-zero blocks when compressing an
image. This feature is already supported by the geom_uzip(4) module
and CLOOP format in general, so it's just a matter of making mkuzip(8)
match. It should be noted, however that this feature while it sounds
great, results in very slight improvement in the overall compression
ratio, since compressing default 16k all-zero block produces only 39
bytes compressed output block, which is 99.8% compression ratio. With
typical average compression ratio of amd64 binaries and data being
around 60-70% the difference between 99.8% and 100.0% is not that
great further diluted by the ratio of number of zero blocks in the
uncompressed image to the overall number of blocks being less than
0.5 (typically). However, this may be important from performance
standpoint, so that kernel are not spinning its wheels decompressing
those empty blocks every time this zero region is read. It could also
be important when you create huge image mostly filled with zero
blocks for testing purposes.
- New feature allowing to de-duplicate output image. It turns out that
if you twist CLOOP format a bit you can do that as well. And unlike
zero-blocks elimination, this gives a noticeable improvement in the
overall compression ratio, reducing output image by something like
3-4% on my test UFS2 3GB image consisting of full FreeBSD base system
plus some of the packages (openjdk, apache etc), about 2.3GB worth of
file data (800+MB compressed). The only caveat is that images created
with this feature "on" would not work on older versions of FeeBSDxi
kernel, hence it's turned off by default.
- provide options to control both features and document them in manual
page.
- merge in all relevant LZMA compression support from the mkulzma(8),
add new option to select between both.
- switch license from ad-hoc beerware into standard 2-clause BSD.
2. geom_uzip(4):
- implement support for de-duplicated images;
- optimize some code paths to handle "all-zero" blocks without reading
any compressed data;
- beef up manual page to explain that geom_uzip(4) is not limited only
to md(4) images. The compressed data can be written to the block
device and accessed directly via magic of GEOM(4) and devfs(4),
including to mount root fs from a compressed drive.
- convert debug log code from being compiled in conditionally into
being present all the time and provide two sysctls to turn it on or
off. Due to intended use of the module, it can be used in
environments where there may not be a luxury to put new kernel with
debug code enabled. Having those options handy allows debug issues
without as much problem by just having access to serial console or
network shell access to a box/appliance. The resulting additional
CPU cycles are just few int comparisons and branches, and those are
minuscule when compared to data decompression which is the main
feature of the module.
- hopefully improve robustness and resiliency of the geom_uzip(4) by
performing some of the data validation / range checking on the TOC
entries and rejecting to attach to an image if those checks fail.
- merge in all relevant LZMA decompression support from the
geom_uncompress(4), enable automatically when appropriate format is
indicated in the header.
- move compilation work into its own worker thread so that it does not
clog g_up. This allows multiple instances work in parallel utilizing
smp cores.
- document new knobs in the manual page.
Reviewed by: adrian
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D5333
2016-02-23 23:59:08 +00:00
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.\"-
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|
.\" Copyright (c) 2004-2016 Maxim Sobolev <sobomax@FreeBSD.org>
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.\" All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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2004-09-10 20:17:31 +00:00
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.\"
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.\" $FreeBSD$
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.\"
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geom_uzip(4), mkuzip(8): Add Zstd image mode
The Zstd format bumps the CLOOP major number to 4 to avoid incompatibility
with older systems. Support in geom_uzip(4) is conditional on the ZSTDIO
kernel option, which is enabled in amd64 GENERIC, but not all in-tree
configurations.
mkuzip(8) was modified slightly to always initialize the nblocks + 1'th
offset in the CLOOP file format. Previously, it was only initialized in the
case where the final compressed block happened to be unaligned w.r.t.
DEV_BSIZE. The "Fake" last+1 block change in r298619 means that the final
compressed block's 'blen' was never correct unless the compressed uzip image
happened to be BSIZE-aligned. This happened in about 1 out of every 512
cases. The zlib and lzma decompressors are probably tolerant of extra trash
following the frame they were told to decode, but Zstd complains that the
input size is incorrect.
Correspondingly, geom_uzip(4) was modified slightly to avoid trashing the
nblocks + 1'th offset when it is known to be initialized to a good value.
This corrects the calculated final real cluster compressed length to match
that printed by mkuzip(8).
mkuzip(8) was refactored somewhat to reduce code duplication and increase
ease of adding other compression formats.
* Input block size validation was pulled out of individual compression
init routines into main().
* Init routines now validate a user-provided compression level or select
an algorithm-specific default, if none was provided.
* A new interface for calculating the maximal compressed size of an
incompressible input block was added for each driver. The generic code
uses it to validate against MAXPHYS as well as to allocate compression
result buffers in the generic code.
* Algorithm selection is now driven by a table lookup, to increase ease of
adding other formats in the future.
mkuzip(8) gained the ability to explicitly specify a compression level with
'-C'. The prior defaults -- 9 for zlib and 6 for lzma -- are maintained.
The new zstd default is 9, to match zlib.
Rather than select lzma or zlib with '-L' or its absense, respectively, a
new argument '-A <algorithm>' is provided to select 'zlib', 'lzma', or
'zstd'. '-L' is considered deprecated, but will probably never be removed.
All of the new features were documented in mkuzip.8; the page was also
cleaned up slightly.
Relnotes: yes
2019-08-13 23:32:56 +00:00
|
|
|
.Dd August 9, 2019
|
2004-09-11 18:39:01 +00:00
|
|
|
.Dt MKUZIP 8
|
2004-09-10 20:17:31 +00:00
|
|
|
.Os
|
|
|
|
|
.Sh NAME
|
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|
|
|
.Nm mkuzip
|
2004-09-10 22:26:31 +00:00
|
|
|
.Nd compress disk image for use with
|
2004-09-10 20:17:31 +00:00
|
|
|
.Xr geom_uzip 4
|
2004-09-10 22:26:31 +00:00
|
|
|
class
|
2004-09-10 20:17:31 +00:00
|
|
|
.Sh SYNOPSIS
|
|
|
|
|
.Nm
|
geom_uzip(4), mkuzip(8): Add Zstd image mode
The Zstd format bumps the CLOOP major number to 4 to avoid incompatibility
with older systems. Support in geom_uzip(4) is conditional on the ZSTDIO
kernel option, which is enabled in amd64 GENERIC, but not all in-tree
configurations.
mkuzip(8) was modified slightly to always initialize the nblocks + 1'th
offset in the CLOOP file format. Previously, it was only initialized in the
case where the final compressed block happened to be unaligned w.r.t.
DEV_BSIZE. The "Fake" last+1 block change in r298619 means that the final
compressed block's 'blen' was never correct unless the compressed uzip image
happened to be BSIZE-aligned. This happened in about 1 out of every 512
cases. The zlib and lzma decompressors are probably tolerant of extra trash
following the frame they were told to decode, but Zstd complains that the
input size is incorrect.
Correspondingly, geom_uzip(4) was modified slightly to avoid trashing the
nblocks + 1'th offset when it is known to be initialized to a good value.
This corrects the calculated final real cluster compressed length to match
that printed by mkuzip(8).
mkuzip(8) was refactored somewhat to reduce code duplication and increase
ease of adding other compression formats.
* Input block size validation was pulled out of individual compression
init routines into main().
* Init routines now validate a user-provided compression level or select
an algorithm-specific default, if none was provided.
* A new interface for calculating the maximal compressed size of an
incompressible input block was added for each driver. The generic code
uses it to validate against MAXPHYS as well as to allocate compression
result buffers in the generic code.
* Algorithm selection is now driven by a table lookup, to increase ease of
adding other formats in the future.
mkuzip(8) gained the ability to explicitly specify a compression level with
'-C'. The prior defaults -- 9 for zlib and 6 for lzma -- are maintained.
The new zstd default is 9, to match zlib.
Rather than select lzma or zlib with '-L' or its absense, respectively, a
new argument '-A <algorithm>' is provided to select 'zlib', 'lzma', or
'zstd'. '-L' is considered deprecated, but will probably never be removed.
All of the new features were documented in mkuzip.8; the page was also
cleaned up slightly.
Relnotes: yes
2019-08-13 23:32:56 +00:00
|
|
|
.Op Fl dSsvZ
|
|
|
|
|
.Op Fl A Ar compression_algorithm
|
|
|
|
|
.Op Fl C Ar compression_level
|
2019-02-19 20:26:03 +00:00
|
|
|
.Op Fl j Ar compression_jobs
|
2004-09-10 20:17:31 +00:00
|
|
|
.Op Fl o Ar outfile
|
|
|
|
|
.Op Fl s Ar cluster_size
|
|
|
|
|
.Ar infile
|
|
|
|
|
.Sh DESCRIPTION
|
|
|
|
|
The
|
|
|
|
|
.Nm
|
2006-03-17 20:48:10 +00:00
|
|
|
utility compresses a disk image file so that the
|
2004-09-10 20:17:31 +00:00
|
|
|
.Xr geom_uzip 4
|
2006-03-17 20:48:10 +00:00
|
|
|
class will be able to decompress the resulting image at run-time.
|
|
|
|
|
This allows for a significant reduction of size of disk image at
|
2004-09-10 22:26:31 +00:00
|
|
|
the expense of some CPU time required to decompress the data each
|
2004-09-11 18:39:01 +00:00
|
|
|
time it is read.
|
2006-09-29 15:20:48 +00:00
|
|
|
The
|
2006-03-17 20:48:10 +00:00
|
|
|
.Nm
|
2006-09-29 15:20:48 +00:00
|
|
|
utility
|
2006-03-17 20:48:10 +00:00
|
|
|
works in two phases:
|
2004-09-10 20:17:31 +00:00
|
|
|
.Bl -enum
|
|
|
|
|
.It
|
|
|
|
|
An
|
|
|
|
|
.Ar infile
|
geom_uzip(4), mkuzip(8): Add Zstd image mode
The Zstd format bumps the CLOOP major number to 4 to avoid incompatibility
with older systems. Support in geom_uzip(4) is conditional on the ZSTDIO
kernel option, which is enabled in amd64 GENERIC, but not all in-tree
configurations.
mkuzip(8) was modified slightly to always initialize the nblocks + 1'th
offset in the CLOOP file format. Previously, it was only initialized in the
case where the final compressed block happened to be unaligned w.r.t.
DEV_BSIZE. The "Fake" last+1 block change in r298619 means that the final
compressed block's 'blen' was never correct unless the compressed uzip image
happened to be BSIZE-aligned. This happened in about 1 out of every 512
cases. The zlib and lzma decompressors are probably tolerant of extra trash
following the frame they were told to decode, but Zstd complains that the
input size is incorrect.
Correspondingly, geom_uzip(4) was modified slightly to avoid trashing the
nblocks + 1'th offset when it is known to be initialized to a good value.
This corrects the calculated final real cluster compressed length to match
that printed by mkuzip(8).
mkuzip(8) was refactored somewhat to reduce code duplication and increase
ease of adding other compression formats.
* Input block size validation was pulled out of individual compression
init routines into main().
* Init routines now validate a user-provided compression level or select
an algorithm-specific default, if none was provided.
* A new interface for calculating the maximal compressed size of an
incompressible input block was added for each driver. The generic code
uses it to validate against MAXPHYS as well as to allocate compression
result buffers in the generic code.
* Algorithm selection is now driven by a table lookup, to increase ease of
adding other formats in the future.
mkuzip(8) gained the ability to explicitly specify a compression level with
'-C'. The prior defaults -- 9 for zlib and 6 for lzma -- are maintained.
The new zstd default is 9, to match zlib.
Rather than select lzma or zlib with '-L' or its absense, respectively, a
new argument '-A <algorithm>' is provided to select 'zlib', 'lzma', or
'zstd'. '-L' is considered deprecated, but will probably never be removed.
All of the new features were documented in mkuzip.8; the page was also
cleaned up slightly.
Relnotes: yes
2019-08-13 23:32:56 +00:00
|
|
|
image is split into clusters; each cluster is compressed.
|
2004-09-10 20:17:31 +00:00
|
|
|
.It
|
geom_uzip(4), mkuzip(8): Add Zstd image mode
The Zstd format bumps the CLOOP major number to 4 to avoid incompatibility
with older systems. Support in geom_uzip(4) is conditional on the ZSTDIO
kernel option, which is enabled in amd64 GENERIC, but not all in-tree
configurations.
mkuzip(8) was modified slightly to always initialize the nblocks + 1'th
offset in the CLOOP file format. Previously, it was only initialized in the
case where the final compressed block happened to be unaligned w.r.t.
DEV_BSIZE. The "Fake" last+1 block change in r298619 means that the final
compressed block's 'blen' was never correct unless the compressed uzip image
happened to be BSIZE-aligned. This happened in about 1 out of every 512
cases. The zlib and lzma decompressors are probably tolerant of extra trash
following the frame they were told to decode, but Zstd complains that the
input size is incorrect.
Correspondingly, geom_uzip(4) was modified slightly to avoid trashing the
nblocks + 1'th offset when it is known to be initialized to a good value.
This corrects the calculated final real cluster compressed length to match
that printed by mkuzip(8).
mkuzip(8) was refactored somewhat to reduce code duplication and increase
ease of adding other compression formats.
* Input block size validation was pulled out of individual compression
init routines into main().
* Init routines now validate a user-provided compression level or select
an algorithm-specific default, if none was provided.
* A new interface for calculating the maximal compressed size of an
incompressible input block was added for each driver. The generic code
uses it to validate against MAXPHYS as well as to allocate compression
result buffers in the generic code.
* Algorithm selection is now driven by a table lookup, to increase ease of
adding other formats in the future.
mkuzip(8) gained the ability to explicitly specify a compression level with
'-C'. The prior defaults -- 9 for zlib and 6 for lzma -- are maintained.
The new zstd default is 9, to match zlib.
Rather than select lzma or zlib with '-L' or its absense, respectively, a
new argument '-A <algorithm>' is provided to select 'zlib', 'lzma', or
'zstd'. '-L' is considered deprecated, but will probably never be removed.
All of the new features were documented in mkuzip.8; the page was also
cleaned up slightly.
Relnotes: yes
2019-08-13 23:32:56 +00:00
|
|
|
The resulting set of compressed clusters is written to the output file.
|
|
|
|
|
In addition, a
|
|
|
|
|
.Dq table of contents
|
|
|
|
|
header is written which allows for efficient seeking.
|
2004-09-10 20:17:31 +00:00
|
|
|
.El
|
|
|
|
|
.Pp
|
|
|
|
|
The options are:
|
2004-09-11 18:39:01 +00:00
|
|
|
.Bl -tag -width indent
|
geom_uzip(4), mkuzip(8): Add Zstd image mode
The Zstd format bumps the CLOOP major number to 4 to avoid incompatibility
with older systems. Support in geom_uzip(4) is conditional on the ZSTDIO
kernel option, which is enabled in amd64 GENERIC, but not all in-tree
configurations.
mkuzip(8) was modified slightly to always initialize the nblocks + 1'th
offset in the CLOOP file format. Previously, it was only initialized in the
case where the final compressed block happened to be unaligned w.r.t.
DEV_BSIZE. The "Fake" last+1 block change in r298619 means that the final
compressed block's 'blen' was never correct unless the compressed uzip image
happened to be BSIZE-aligned. This happened in about 1 out of every 512
cases. The zlib and lzma decompressors are probably tolerant of extra trash
following the frame they were told to decode, but Zstd complains that the
input size is incorrect.
Correspondingly, geom_uzip(4) was modified slightly to avoid trashing the
nblocks + 1'th offset when it is known to be initialized to a good value.
This corrects the calculated final real cluster compressed length to match
that printed by mkuzip(8).
mkuzip(8) was refactored somewhat to reduce code duplication and increase
ease of adding other compression formats.
* Input block size validation was pulled out of individual compression
init routines into main().
* Init routines now validate a user-provided compression level or select
an algorithm-specific default, if none was provided.
* A new interface for calculating the maximal compressed size of an
incompressible input block was added for each driver. The generic code
uses it to validate against MAXPHYS as well as to allocate compression
result buffers in the generic code.
* Algorithm selection is now driven by a table lookup, to increase ease of
adding other formats in the future.
mkuzip(8) gained the ability to explicitly specify a compression level with
'-C'. The prior defaults -- 9 for zlib and 6 for lzma -- are maintained.
The new zstd default is 9, to match zlib.
Rather than select lzma or zlib with '-L' or its absense, respectively, a
new argument '-A <algorithm>' is provided to select 'zlib', 'lzma', or
'zstd'. '-L' is considered deprecated, but will probably never be removed.
All of the new features were documented in mkuzip.8; the page was also
cleaned up slightly.
Relnotes: yes
2019-08-13 23:32:56 +00:00
|
|
|
.It Fl A Op Ar lzma | Ar zlib | Ar zstd
|
|
|
|
|
Select a specific compression algorithm.
|
|
|
|
|
If this option is not provided, the default is
|
|
|
|
|
.Ar zlib .
|
|
|
|
|
.Pp
|
|
|
|
|
The
|
|
|
|
|
.Ar lzma
|
|
|
|
|
algorithm provides noticeable better compression levels than zlib on the same
|
|
|
|
|
data set.
|
|
|
|
|
It has vastly slower compression speed and moderately slower decompression
|
|
|
|
|
speed.
|
|
|
|
|
.Pp
|
|
|
|
|
The
|
|
|
|
|
.Ar zstd
|
|
|
|
|
algorithm provides better compression levels than zlib on the same data set.
|
|
|
|
|
It also has faster compression and decompression speed than zlib.
|
|
|
|
|
In the very high compression
|
|
|
|
|
.Dq level
|
|
|
|
|
settings, it does not offer quite as high a compression ratio as
|
|
|
|
|
.Ar lzma .
|
|
|
|
|
However, its decompression speed does not suffer at high compression
|
|
|
|
|
.Dq levels .
|
|
|
|
|
.It Fl C Ar compression_level
|
|
|
|
|
Select the integer compression level used to parameterize the chosen
|
|
|
|
|
compression algorithm.
|
|
|
|
|
.Pp
|
|
|
|
|
For any given algorithm, a lesser number selects a faster compression mode.
|
|
|
|
|
A greater number selects a slower compression mode.
|
|
|
|
|
Typically, for the same algorithm, a greater
|
|
|
|
|
.Ar compression_level
|
|
|
|
|
provides better final compression ratio.
|
|
|
|
|
.Pp
|
|
|
|
|
For
|
|
|
|
|
.Ar lzma ,
|
|
|
|
|
the range of valid compression levels is
|
|
|
|
|
.Va 0-9 .
|
|
|
|
|
The
|
|
|
|
|
.Nm
|
|
|
|
|
default for lzma is
|
|
|
|
|
.Va 6 .
|
|
|
|
|
.Pp
|
|
|
|
|
For
|
|
|
|
|
.Ar zlib ,
|
|
|
|
|
the range of valid compression levels is
|
|
|
|
|
.Va 1-9 .
|
|
|
|
|
The
|
|
|
|
|
.Nm
|
|
|
|
|
default for zlib is
|
|
|
|
|
.Va 9 .
|
|
|
|
|
.Pp
|
|
|
|
|
For
|
|
|
|
|
.Ar zstd ,
|
|
|
|
|
the range of valid compression levels is currently
|
|
|
|
|
.Va 1-19 .
|
|
|
|
|
The
|
|
|
|
|
.Nm
|
|
|
|
|
default for zstd is
|
|
|
|
|
.Va 9 .
|
|
|
|
|
.It Fl d
|
|
|
|
|
Enable de-duplication.
|
|
|
|
|
When the option is enabled
|
|
|
|
|
.Nm
|
|
|
|
|
detects identical blocks in the input and replaces each subsequent occurrence
|
|
|
|
|
of such block with pointer to the very first one in the output.
|
|
|
|
|
Setting this option results is moderate decrease of compressed image size,
|
|
|
|
|
typically around 3-5% of a final size of the compressed image.
|
2019-02-19 20:26:03 +00:00
|
|
|
.It Fl j Ar compression_jobs
|
|
|
|
|
Specify the number of compression jobs that
|
|
|
|
|
.Nm
|
|
|
|
|
runs in parallel to speed up compression.
|
|
|
|
|
When option is not specified the number of jobs set to be equal
|
|
|
|
|
to the value of
|
|
|
|
|
.Va hw.ncpu
|
|
|
|
|
.Xr sysctl 8
|
|
|
|
|
variable.
|
geom_uzip(4), mkuzip(8): Add Zstd image mode
The Zstd format bumps the CLOOP major number to 4 to avoid incompatibility
with older systems. Support in geom_uzip(4) is conditional on the ZSTDIO
kernel option, which is enabled in amd64 GENERIC, but not all in-tree
configurations.
mkuzip(8) was modified slightly to always initialize the nblocks + 1'th
offset in the CLOOP file format. Previously, it was only initialized in the
case where the final compressed block happened to be unaligned w.r.t.
DEV_BSIZE. The "Fake" last+1 block change in r298619 means that the final
compressed block's 'blen' was never correct unless the compressed uzip image
happened to be BSIZE-aligned. This happened in about 1 out of every 512
cases. The zlib and lzma decompressors are probably tolerant of extra trash
following the frame they were told to decode, but Zstd complains that the
input size is incorrect.
Correspondingly, geom_uzip(4) was modified slightly to avoid trashing the
nblocks + 1'th offset when it is known to be initialized to a good value.
This corrects the calculated final real cluster compressed length to match
that printed by mkuzip(8).
mkuzip(8) was refactored somewhat to reduce code duplication and increase
ease of adding other compression formats.
* Input block size validation was pulled out of individual compression
init routines into main().
* Init routines now validate a user-provided compression level or select
an algorithm-specific default, if none was provided.
* A new interface for calculating the maximal compressed size of an
incompressible input block was added for each driver. The generic code
uses it to validate against MAXPHYS as well as to allocate compression
result buffers in the generic code.
* Algorithm selection is now driven by a table lookup, to increase ease of
adding other formats in the future.
mkuzip(8) gained the ability to explicitly specify a compression level with
'-C'. The prior defaults -- 9 for zlib and 6 for lzma -- are maintained.
The new zstd default is 9, to match zlib.
Rather than select lzma or zlib with '-L' or its absense, respectively, a
new argument '-A <algorithm>' is provided to select 'zlib', 'lzma', or
'zstd'. '-L' is considered deprecated, but will probably never be removed.
All of the new features were documented in mkuzip.8; the page was also
cleaned up slightly.
Relnotes: yes
2019-08-13 23:32:56 +00:00
|
|
|
.It Op Fl L
|
|
|
|
|
Legacy flag that indicates the same thing as
|
|
|
|
|
.Dq Fl A Ar lzma .
|
2004-09-10 20:17:31 +00:00
|
|
|
.It Fl o Ar outfile
|
2006-03-17 20:48:10 +00:00
|
|
|
Name of the output file
|
2004-09-10 20:17:31 +00:00
|
|
|
.Ar outfile .
|
|
|
|
|
The default is to use the input name with the suffix
|
2017-02-11 23:40:57 +00:00
|
|
|
.Pa .uzip
|
Improve mkuzip(8) and geom_uzip(4), merge in LZMA support from mkulzma(8)
and geom_uncompress(4):
1. mkuzip(8):
- Proper support for eliminating all-zero blocks when compressing an
image. This feature is already supported by the geom_uzip(4) module
and CLOOP format in general, so it's just a matter of making mkuzip(8)
match. It should be noted, however that this feature while it sounds
great, results in very slight improvement in the overall compression
ratio, since compressing default 16k all-zero block produces only 39
bytes compressed output block, which is 99.8% compression ratio. With
typical average compression ratio of amd64 binaries and data being
around 60-70% the difference between 99.8% and 100.0% is not that
great further diluted by the ratio of number of zero blocks in the
uncompressed image to the overall number of blocks being less than
0.5 (typically). However, this may be important from performance
standpoint, so that kernel are not spinning its wheels decompressing
those empty blocks every time this zero region is read. It could also
be important when you create huge image mostly filled with zero
blocks for testing purposes.
- New feature allowing to de-duplicate output image. It turns out that
if you twist CLOOP format a bit you can do that as well. And unlike
zero-blocks elimination, this gives a noticeable improvement in the
overall compression ratio, reducing output image by something like
3-4% on my test UFS2 3GB image consisting of full FreeBSD base system
plus some of the packages (openjdk, apache etc), about 2.3GB worth of
file data (800+MB compressed). The only caveat is that images created
with this feature "on" would not work on older versions of FeeBSDxi
kernel, hence it's turned off by default.
- provide options to control both features and document them in manual
page.
- merge in all relevant LZMA compression support from the mkulzma(8),
add new option to select between both.
- switch license from ad-hoc beerware into standard 2-clause BSD.
2. geom_uzip(4):
- implement support for de-duplicated images;
- optimize some code paths to handle "all-zero" blocks without reading
any compressed data;
- beef up manual page to explain that geom_uzip(4) is not limited only
to md(4) images. The compressed data can be written to the block
device and accessed directly via magic of GEOM(4) and devfs(4),
including to mount root fs from a compressed drive.
- convert debug log code from being compiled in conditionally into
being present all the time and provide two sysctls to turn it on or
off. Due to intended use of the module, it can be used in
environments where there may not be a luxury to put new kernel with
debug code enabled. Having those options handy allows debug issues
without as much problem by just having access to serial console or
network shell access to a box/appliance. The resulting additional
CPU cycles are just few int comparisons and branches, and those are
minuscule when compared to data decompression which is the main
feature of the module.
- hopefully improve robustness and resiliency of the geom_uzip(4) by
performing some of the data validation / range checking on the TOC
entries and rejecting to attach to an image if those checks fail.
- merge in all relevant LZMA decompression support from the
geom_uncompress(4), enable automatically when appropriate format is
indicated in the header.
- move compilation work into its own worker thread so that it does not
clog g_up. This allows multiple instances work in parallel utilizing
smp cores.
- document new knobs in the manual page.
Reviewed by: adrian
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D5333
2016-02-23 23:59:08 +00:00
|
|
|
for the
|
|
|
|
|
.Xr zlib 3
|
|
|
|
|
compression or
|
|
|
|
|
.Pa .ulzma
|
|
|
|
|
for the
|
|
|
|
|
.Xr lzma 3 .
|
2019-02-19 20:26:03 +00:00
|
|
|
.It Fl S
|
|
|
|
|
Print summary about the compression ratio as well as output
|
|
|
|
|
file size after file has been processed.
|
2004-09-10 20:17:31 +00:00
|
|
|
.It Fl s Ar cluster_size
|
2006-03-17 20:48:10 +00:00
|
|
|
Split the image into clusters of
|
2004-09-10 20:17:31 +00:00
|
|
|
.Ar cluster_size
|
2006-03-17 20:48:10 +00:00
|
|
|
bytes, 16384 bytes by default.
|
2004-09-11 18:39:01 +00:00
|
|
|
The
|
2004-09-10 20:17:31 +00:00
|
|
|
.Ar cluster_size
|
2004-09-11 18:39:01 +00:00
|
|
|
should be a multiple of 512 bytes.
|
2004-09-10 20:17:31 +00:00
|
|
|
.It Fl v
|
|
|
|
|
Display verbose messages.
|
Improve mkuzip(8) and geom_uzip(4), merge in LZMA support from mkulzma(8)
and geom_uncompress(4):
1. mkuzip(8):
- Proper support for eliminating all-zero blocks when compressing an
image. This feature is already supported by the geom_uzip(4) module
and CLOOP format in general, so it's just a matter of making mkuzip(8)
match. It should be noted, however that this feature while it sounds
great, results in very slight improvement in the overall compression
ratio, since compressing default 16k all-zero block produces only 39
bytes compressed output block, which is 99.8% compression ratio. With
typical average compression ratio of amd64 binaries and data being
around 60-70% the difference between 99.8% and 100.0% is not that
great further diluted by the ratio of number of zero blocks in the
uncompressed image to the overall number of blocks being less than
0.5 (typically). However, this may be important from performance
standpoint, so that kernel are not spinning its wheels decompressing
those empty blocks every time this zero region is read. It could also
be important when you create huge image mostly filled with zero
blocks for testing purposes.
- New feature allowing to de-duplicate output image. It turns out that
if you twist CLOOP format a bit you can do that as well. And unlike
zero-blocks elimination, this gives a noticeable improvement in the
overall compression ratio, reducing output image by something like
3-4% on my test UFS2 3GB image consisting of full FreeBSD base system
plus some of the packages (openjdk, apache etc), about 2.3GB worth of
file data (800+MB compressed). The only caveat is that images created
with this feature "on" would not work on older versions of FeeBSDxi
kernel, hence it's turned off by default.
- provide options to control both features and document them in manual
page.
- merge in all relevant LZMA compression support from the mkulzma(8),
add new option to select between both.
- switch license from ad-hoc beerware into standard 2-clause BSD.
2. geom_uzip(4):
- implement support for de-duplicated images;
- optimize some code paths to handle "all-zero" blocks without reading
any compressed data;
- beef up manual page to explain that geom_uzip(4) is not limited only
to md(4) images. The compressed data can be written to the block
device and accessed directly via magic of GEOM(4) and devfs(4),
including to mount root fs from a compressed drive.
- convert debug log code from being compiled in conditionally into
being present all the time and provide two sysctls to turn it on or
off. Due to intended use of the module, it can be used in
environments where there may not be a luxury to put new kernel with
debug code enabled. Having those options handy allows debug issues
without as much problem by just having access to serial console or
network shell access to a box/appliance. The resulting additional
CPU cycles are just few int comparisons and branches, and those are
minuscule when compared to data decompression which is the main
feature of the module.
- hopefully improve robustness and resiliency of the geom_uzip(4) by
performing some of the data validation / range checking on the TOC
entries and rejecting to attach to an image if those checks fail.
- merge in all relevant LZMA decompression support from the
geom_uncompress(4), enable automatically when appropriate format is
indicated in the header.
- move compilation work into its own worker thread so that it does not
clog g_up. This allows multiple instances work in parallel utilizing
smp cores.
- document new knobs in the manual page.
Reviewed by: adrian
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D5333
2016-02-23 23:59:08 +00:00
|
|
|
.It Fl Z
|
geom_uzip(4), mkuzip(8): Add Zstd image mode
The Zstd format bumps the CLOOP major number to 4 to avoid incompatibility
with older systems. Support in geom_uzip(4) is conditional on the ZSTDIO
kernel option, which is enabled in amd64 GENERIC, but not all in-tree
configurations.
mkuzip(8) was modified slightly to always initialize the nblocks + 1'th
offset in the CLOOP file format. Previously, it was only initialized in the
case where the final compressed block happened to be unaligned w.r.t.
DEV_BSIZE. The "Fake" last+1 block change in r298619 means that the final
compressed block's 'blen' was never correct unless the compressed uzip image
happened to be BSIZE-aligned. This happened in about 1 out of every 512
cases. The zlib and lzma decompressors are probably tolerant of extra trash
following the frame they were told to decode, but Zstd complains that the
input size is incorrect.
Correspondingly, geom_uzip(4) was modified slightly to avoid trashing the
nblocks + 1'th offset when it is known to be initialized to a good value.
This corrects the calculated final real cluster compressed length to match
that printed by mkuzip(8).
mkuzip(8) was refactored somewhat to reduce code duplication and increase
ease of adding other compression formats.
* Input block size validation was pulled out of individual compression
init routines into main().
* Init routines now validate a user-provided compression level or select
an algorithm-specific default, if none was provided.
* A new interface for calculating the maximal compressed size of an
incompressible input block was added for each driver. The generic code
uses it to validate against MAXPHYS as well as to allocate compression
result buffers in the generic code.
* Algorithm selection is now driven by a table lookup, to increase ease of
adding other formats in the future.
mkuzip(8) gained the ability to explicitly specify a compression level with
'-C'. The prior defaults -- 9 for zlib and 6 for lzma -- are maintained.
The new zstd default is 9, to match zlib.
Rather than select lzma or zlib with '-L' or its absense, respectively, a
new argument '-A <algorithm>' is provided to select 'zlib', 'lzma', or
'zstd'. '-L' is considered deprecated, but will probably never be removed.
All of the new features were documented in mkuzip.8; the page was also
cleaned up slightly.
Relnotes: yes
2019-08-13 23:32:56 +00:00
|
|
|
Disable zero-block detection and elimination.
|
|
|
|
|
When this option is set,
|
Improve mkuzip(8) and geom_uzip(4), merge in LZMA support from mkulzma(8)
and geom_uncompress(4):
1. mkuzip(8):
- Proper support for eliminating all-zero blocks when compressing an
image. This feature is already supported by the geom_uzip(4) module
and CLOOP format in general, so it's just a matter of making mkuzip(8)
match. It should be noted, however that this feature while it sounds
great, results in very slight improvement in the overall compression
ratio, since compressing default 16k all-zero block produces only 39
bytes compressed output block, which is 99.8% compression ratio. With
typical average compression ratio of amd64 binaries and data being
around 60-70% the difference between 99.8% and 100.0% is not that
great further diluted by the ratio of number of zero blocks in the
uncompressed image to the overall number of blocks being less than
0.5 (typically). However, this may be important from performance
standpoint, so that kernel are not spinning its wheels decompressing
those empty blocks every time this zero region is read. It could also
be important when you create huge image mostly filled with zero
blocks for testing purposes.
- New feature allowing to de-duplicate output image. It turns out that
if you twist CLOOP format a bit you can do that as well. And unlike
zero-blocks elimination, this gives a noticeable improvement in the
overall compression ratio, reducing output image by something like
3-4% on my test UFS2 3GB image consisting of full FreeBSD base system
plus some of the packages (openjdk, apache etc), about 2.3GB worth of
file data (800+MB compressed). The only caveat is that images created
with this feature "on" would not work on older versions of FeeBSDxi
kernel, hence it's turned off by default.
- provide options to control both features and document them in manual
page.
- merge in all relevant LZMA compression support from the mkulzma(8),
add new option to select between both.
- switch license from ad-hoc beerware into standard 2-clause BSD.
2. geom_uzip(4):
- implement support for de-duplicated images;
- optimize some code paths to handle "all-zero" blocks without reading
any compressed data;
- beef up manual page to explain that geom_uzip(4) is not limited only
to md(4) images. The compressed data can be written to the block
device and accessed directly via magic of GEOM(4) and devfs(4),
including to mount root fs from a compressed drive.
- convert debug log code from being compiled in conditionally into
being present all the time and provide two sysctls to turn it on or
off. Due to intended use of the module, it can be used in
environments where there may not be a luxury to put new kernel with
debug code enabled. Having those options handy allows debug issues
without as much problem by just having access to serial console or
network shell access to a box/appliance. The resulting additional
CPU cycles are just few int comparisons and branches, and those are
minuscule when compared to data decompression which is the main
feature of the module.
- hopefully improve robustness and resiliency of the geom_uzip(4) by
performing some of the data validation / range checking on the TOC
entries and rejecting to attach to an image if those checks fail.
- merge in all relevant LZMA decompression support from the
geom_uncompress(4), enable automatically when appropriate format is
indicated in the header.
- move compilation work into its own worker thread so that it does not
clog g_up. This allows multiple instances work in parallel utilizing
smp cores.
- document new knobs in the manual page.
Reviewed by: adrian
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D5333
2016-02-23 23:59:08 +00:00
|
|
|
.Nm
|
geom_uzip(4), mkuzip(8): Add Zstd image mode
The Zstd format bumps the CLOOP major number to 4 to avoid incompatibility
with older systems. Support in geom_uzip(4) is conditional on the ZSTDIO
kernel option, which is enabled in amd64 GENERIC, but not all in-tree
configurations.
mkuzip(8) was modified slightly to always initialize the nblocks + 1'th
offset in the CLOOP file format. Previously, it was only initialized in the
case where the final compressed block happened to be unaligned w.r.t.
DEV_BSIZE. The "Fake" last+1 block change in r298619 means that the final
compressed block's 'blen' was never correct unless the compressed uzip image
happened to be BSIZE-aligned. This happened in about 1 out of every 512
cases. The zlib and lzma decompressors are probably tolerant of extra trash
following the frame they were told to decode, but Zstd complains that the
input size is incorrect.
Correspondingly, geom_uzip(4) was modified slightly to avoid trashing the
nblocks + 1'th offset when it is known to be initialized to a good value.
This corrects the calculated final real cluster compressed length to match
that printed by mkuzip(8).
mkuzip(8) was refactored somewhat to reduce code duplication and increase
ease of adding other compression formats.
* Input block size validation was pulled out of individual compression
init routines into main().
* Init routines now validate a user-provided compression level or select
an algorithm-specific default, if none was provided.
* A new interface for calculating the maximal compressed size of an
incompressible input block was added for each driver. The generic code
uses it to validate against MAXPHYS as well as to allocate compression
result buffers in the generic code.
* Algorithm selection is now driven by a table lookup, to increase ease of
adding other formats in the future.
mkuzip(8) gained the ability to explicitly specify a compression level with
'-C'. The prior defaults -- 9 for zlib and 6 for lzma -- are maintained.
The new zstd default is 9, to match zlib.
Rather than select lzma or zlib with '-L' or its absense, respectively, a
new argument '-A <algorithm>' is provided to select 'zlib', 'lzma', or
'zstd'. '-L' is considered deprecated, but will probably never be removed.
All of the new features were documented in mkuzip.8; the page was also
cleaned up slightly.
Relnotes: yes
2019-08-13 23:32:56 +00:00
|
|
|
compresses blocks of zero bytes just as it would any other block.
|
|
|
|
|
When the option is not set,
|
Improve mkuzip(8) and geom_uzip(4), merge in LZMA support from mkulzma(8)
and geom_uncompress(4):
1. mkuzip(8):
- Proper support for eliminating all-zero blocks when compressing an
image. This feature is already supported by the geom_uzip(4) module
and CLOOP format in general, so it's just a matter of making mkuzip(8)
match. It should be noted, however that this feature while it sounds
great, results in very slight improvement in the overall compression
ratio, since compressing default 16k all-zero block produces only 39
bytes compressed output block, which is 99.8% compression ratio. With
typical average compression ratio of amd64 binaries and data being
around 60-70% the difference between 99.8% and 100.0% is not that
great further diluted by the ratio of number of zero blocks in the
uncompressed image to the overall number of blocks being less than
0.5 (typically). However, this may be important from performance
standpoint, so that kernel are not spinning its wheels decompressing
those empty blocks every time this zero region is read. It could also
be important when you create huge image mostly filled with zero
blocks for testing purposes.
- New feature allowing to de-duplicate output image. It turns out that
if you twist CLOOP format a bit you can do that as well. And unlike
zero-blocks elimination, this gives a noticeable improvement in the
overall compression ratio, reducing output image by something like
3-4% on my test UFS2 3GB image consisting of full FreeBSD base system
plus some of the packages (openjdk, apache etc), about 2.3GB worth of
file data (800+MB compressed). The only caveat is that images created
with this feature "on" would not work on older versions of FeeBSDxi
kernel, hence it's turned off by default.
- provide options to control both features and document them in manual
page.
- merge in all relevant LZMA compression support from the mkulzma(8),
add new option to select between both.
- switch license from ad-hoc beerware into standard 2-clause BSD.
2. geom_uzip(4):
- implement support for de-duplicated images;
- optimize some code paths to handle "all-zero" blocks without reading
any compressed data;
- beef up manual page to explain that geom_uzip(4) is not limited only
to md(4) images. The compressed data can be written to the block
device and accessed directly via magic of GEOM(4) and devfs(4),
including to mount root fs from a compressed drive.
- convert debug log code from being compiled in conditionally into
being present all the time and provide two sysctls to turn it on or
off. Due to intended use of the module, it can be used in
environments where there may not be a luxury to put new kernel with
debug code enabled. Having those options handy allows debug issues
without as much problem by just having access to serial console or
network shell access to a box/appliance. The resulting additional
CPU cycles are just few int comparisons and branches, and those are
minuscule when compared to data decompression which is the main
feature of the module.
- hopefully improve robustness and resiliency of the geom_uzip(4) by
performing some of the data validation / range checking on the TOC
entries and rejecting to attach to an image if those checks fail.
- merge in all relevant LZMA decompression support from the
geom_uncompress(4), enable automatically when appropriate format is
indicated in the header.
- move compilation work into its own worker thread so that it does not
clog g_up. This allows multiple instances work in parallel utilizing
smp cores.
- document new knobs in the manual page.
Reviewed by: adrian
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D5333
2016-02-23 23:59:08 +00:00
|
|
|
.Nm
|
geom_uzip(4), mkuzip(8): Add Zstd image mode
The Zstd format bumps the CLOOP major number to 4 to avoid incompatibility
with older systems. Support in geom_uzip(4) is conditional on the ZSTDIO
kernel option, which is enabled in amd64 GENERIC, but not all in-tree
configurations.
mkuzip(8) was modified slightly to always initialize the nblocks + 1'th
offset in the CLOOP file format. Previously, it was only initialized in the
case where the final compressed block happened to be unaligned w.r.t.
DEV_BSIZE. The "Fake" last+1 block change in r298619 means that the final
compressed block's 'blen' was never correct unless the compressed uzip image
happened to be BSIZE-aligned. This happened in about 1 out of every 512
cases. The zlib and lzma decompressors are probably tolerant of extra trash
following the frame they were told to decode, but Zstd complains that the
input size is incorrect.
Correspondingly, geom_uzip(4) was modified slightly to avoid trashing the
nblocks + 1'th offset when it is known to be initialized to a good value.
This corrects the calculated final real cluster compressed length to match
that printed by mkuzip(8).
mkuzip(8) was refactored somewhat to reduce code duplication and increase
ease of adding other compression formats.
* Input block size validation was pulled out of individual compression
init routines into main().
* Init routines now validate a user-provided compression level or select
an algorithm-specific default, if none was provided.
* A new interface for calculating the maximal compressed size of an
incompressible input block was added for each driver. The generic code
uses it to validate against MAXPHYS as well as to allocate compression
result buffers in the generic code.
* Algorithm selection is now driven by a table lookup, to increase ease of
adding other formats in the future.
mkuzip(8) gained the ability to explicitly specify a compression level with
'-C'. The prior defaults -- 9 for zlib and 6 for lzma -- are maintained.
The new zstd default is 9, to match zlib.
Rather than select lzma or zlib with '-L' or its absense, respectively, a
new argument '-A <algorithm>' is provided to select 'zlib', 'lzma', or
'zstd'. '-L' is considered deprecated, but will probably never be removed.
All of the new features were documented in mkuzip.8; the page was also
cleaned up slightly.
Relnotes: yes
2019-08-13 23:32:56 +00:00
|
|
|
detects and compresses zero blocks in a space-efficient way.
|
Improve mkuzip(8) and geom_uzip(4), merge in LZMA support from mkulzma(8)
and geom_uncompress(4):
1. mkuzip(8):
- Proper support for eliminating all-zero blocks when compressing an
image. This feature is already supported by the geom_uzip(4) module
and CLOOP format in general, so it's just a matter of making mkuzip(8)
match. It should be noted, however that this feature while it sounds
great, results in very slight improvement in the overall compression
ratio, since compressing default 16k all-zero block produces only 39
bytes compressed output block, which is 99.8% compression ratio. With
typical average compression ratio of amd64 binaries and data being
around 60-70% the difference between 99.8% and 100.0% is not that
great further diluted by the ratio of number of zero blocks in the
uncompressed image to the overall number of blocks being less than
0.5 (typically). However, this may be important from performance
standpoint, so that kernel are not spinning its wheels decompressing
those empty blocks every time this zero region is read. It could also
be important when you create huge image mostly filled with zero
blocks for testing purposes.
- New feature allowing to de-duplicate output image. It turns out that
if you twist CLOOP format a bit you can do that as well. And unlike
zero-blocks elimination, this gives a noticeable improvement in the
overall compression ratio, reducing output image by something like
3-4% on my test UFS2 3GB image consisting of full FreeBSD base system
plus some of the packages (openjdk, apache etc), about 2.3GB worth of
file data (800+MB compressed). The only caveat is that images created
with this feature "on" would not work on older versions of FeeBSDxi
kernel, hence it's turned off by default.
- provide options to control both features and document them in manual
page.
- merge in all relevant LZMA compression support from the mkulzma(8),
add new option to select between both.
- switch license from ad-hoc beerware into standard 2-clause BSD.
2. geom_uzip(4):
- implement support for de-duplicated images;
- optimize some code paths to handle "all-zero" blocks without reading
any compressed data;
- beef up manual page to explain that geom_uzip(4) is not limited only
to md(4) images. The compressed data can be written to the block
device and accessed directly via magic of GEOM(4) and devfs(4),
including to mount root fs from a compressed drive.
- convert debug log code from being compiled in conditionally into
being present all the time and provide two sysctls to turn it on or
off. Due to intended use of the module, it can be used in
environments where there may not be a luxury to put new kernel with
debug code enabled. Having those options handy allows debug issues
without as much problem by just having access to serial console or
network shell access to a box/appliance. The resulting additional
CPU cycles are just few int comparisons and branches, and those are
minuscule when compared to data decompression which is the main
feature of the module.
- hopefully improve robustness and resiliency of the geom_uzip(4) by
performing some of the data validation / range checking on the TOC
entries and rejecting to attach to an image if those checks fail.
- merge in all relevant LZMA decompression support from the
geom_uncompress(4), enable automatically when appropriate format is
indicated in the header.
- move compilation work into its own worker thread so that it does not
clog g_up. This allows multiple instances work in parallel utilizing
smp cores.
- document new knobs in the manual page.
Reviewed by: adrian
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D5333
2016-02-23 23:59:08 +00:00
|
|
|
Setting
|
|
|
|
|
.Fl Z
|
geom_uzip(4), mkuzip(8): Add Zstd image mode
The Zstd format bumps the CLOOP major number to 4 to avoid incompatibility
with older systems. Support in geom_uzip(4) is conditional on the ZSTDIO
kernel option, which is enabled in amd64 GENERIC, but not all in-tree
configurations.
mkuzip(8) was modified slightly to always initialize the nblocks + 1'th
offset in the CLOOP file format. Previously, it was only initialized in the
case where the final compressed block happened to be unaligned w.r.t.
DEV_BSIZE. The "Fake" last+1 block change in r298619 means that the final
compressed block's 'blen' was never correct unless the compressed uzip image
happened to be BSIZE-aligned. This happened in about 1 out of every 512
cases. The zlib and lzma decompressors are probably tolerant of extra trash
following the frame they were told to decode, but Zstd complains that the
input size is incorrect.
Correspondingly, geom_uzip(4) was modified slightly to avoid trashing the
nblocks + 1'th offset when it is known to be initialized to a good value.
This corrects the calculated final real cluster compressed length to match
that printed by mkuzip(8).
mkuzip(8) was refactored somewhat to reduce code duplication and increase
ease of adding other compression formats.
* Input block size validation was pulled out of individual compression
init routines into main().
* Init routines now validate a user-provided compression level or select
an algorithm-specific default, if none was provided.
* A new interface for calculating the maximal compressed size of an
incompressible input block was added for each driver. The generic code
uses it to validate against MAXPHYS as well as to allocate compression
result buffers in the generic code.
* Algorithm selection is now driven by a table lookup, to increase ease of
adding other formats in the future.
mkuzip(8) gained the ability to explicitly specify a compression level with
'-C'. The prior defaults -- 9 for zlib and 6 for lzma -- are maintained.
The new zstd default is 9, to match zlib.
Rather than select lzma or zlib with '-L' or its absense, respectively, a
new argument '-A <algorithm>' is provided to select 'zlib', 'lzma', or
'zstd'. '-L' is considered deprecated, but will probably never be removed.
All of the new features were documented in mkuzip.8; the page was also
cleaned up slightly.
Relnotes: yes
2019-08-13 23:32:56 +00:00
|
|
|
increases compressed image sizes slightly, typically less than 0.1%.
|
2004-09-10 20:17:31 +00:00
|
|
|
.El
|
geom_uzip(4), mkuzip(8): Add Zstd image mode
The Zstd format bumps the CLOOP major number to 4 to avoid incompatibility
with older systems. Support in geom_uzip(4) is conditional on the ZSTDIO
kernel option, which is enabled in amd64 GENERIC, but not all in-tree
configurations.
mkuzip(8) was modified slightly to always initialize the nblocks + 1'th
offset in the CLOOP file format. Previously, it was only initialized in the
case where the final compressed block happened to be unaligned w.r.t.
DEV_BSIZE. The "Fake" last+1 block change in r298619 means that the final
compressed block's 'blen' was never correct unless the compressed uzip image
happened to be BSIZE-aligned. This happened in about 1 out of every 512
cases. The zlib and lzma decompressors are probably tolerant of extra trash
following the frame they were told to decode, but Zstd complains that the
input size is incorrect.
Correspondingly, geom_uzip(4) was modified slightly to avoid trashing the
nblocks + 1'th offset when it is known to be initialized to a good value.
This corrects the calculated final real cluster compressed length to match
that printed by mkuzip(8).
mkuzip(8) was refactored somewhat to reduce code duplication and increase
ease of adding other compression formats.
* Input block size validation was pulled out of individual compression
init routines into main().
* Init routines now validate a user-provided compression level or select
an algorithm-specific default, if none was provided.
* A new interface for calculating the maximal compressed size of an
incompressible input block was added for each driver. The generic code
uses it to validate against MAXPHYS as well as to allocate compression
result buffers in the generic code.
* Algorithm selection is now driven by a table lookup, to increase ease of
adding other formats in the future.
mkuzip(8) gained the ability to explicitly specify a compression level with
'-C'. The prior defaults -- 9 for zlib and 6 for lzma -- are maintained.
The new zstd default is 9, to match zlib.
Rather than select lzma or zlib with '-L' or its absense, respectively, a
new argument '-A <algorithm>' is provided to select 'zlib', 'lzma', or
'zstd'. '-L' is considered deprecated, but will probably never be removed.
All of the new features were documented in mkuzip.8; the page was also
cleaned up slightly.
Relnotes: yes
2019-08-13 23:32:56 +00:00
|
|
|
.Sh IMPLEMENTATION NOTES
|
|
|
|
|
The compression ratio largely depends on the compression algorithm, level, and
|
|
|
|
|
cluster size used.
|
|
|
|
|
For large cluster sizes (16kB and higher), typical overall image compression
|
|
|
|
|
ratios with
|
|
|
|
|
.Xr zlib 3
|
2006-03-17 20:48:10 +00:00
|
|
|
are only 1-2% less than those achieved with
|
geom_uzip(4), mkuzip(8): Add Zstd image mode
The Zstd format bumps the CLOOP major number to 4 to avoid incompatibility
with older systems. Support in geom_uzip(4) is conditional on the ZSTDIO
kernel option, which is enabled in amd64 GENERIC, but not all in-tree
configurations.
mkuzip(8) was modified slightly to always initialize the nblocks + 1'th
offset in the CLOOP file format. Previously, it was only initialized in the
case where the final compressed block happened to be unaligned w.r.t.
DEV_BSIZE. The "Fake" last+1 block change in r298619 means that the final
compressed block's 'blen' was never correct unless the compressed uzip image
happened to be BSIZE-aligned. This happened in about 1 out of every 512
cases. The zlib and lzma decompressors are probably tolerant of extra trash
following the frame they were told to decode, but Zstd complains that the
input size is incorrect.
Correspondingly, geom_uzip(4) was modified slightly to avoid trashing the
nblocks + 1'th offset when it is known to be initialized to a good value.
This corrects the calculated final real cluster compressed length to match
that printed by mkuzip(8).
mkuzip(8) was refactored somewhat to reduce code duplication and increase
ease of adding other compression formats.
* Input block size validation was pulled out of individual compression
init routines into main().
* Init routines now validate a user-provided compression level or select
an algorithm-specific default, if none was provided.
* A new interface for calculating the maximal compressed size of an
incompressible input block was added for each driver. The generic code
uses it to validate against MAXPHYS as well as to allocate compression
result buffers in the generic code.
* Algorithm selection is now driven by a table lookup, to increase ease of
adding other formats in the future.
mkuzip(8) gained the ability to explicitly specify a compression level with
'-C'. The prior defaults -- 9 for zlib and 6 for lzma -- are maintained.
The new zstd default is 9, to match zlib.
Rather than select lzma or zlib with '-L' or its absense, respectively, a
new argument '-A <algorithm>' is provided to select 'zlib', 'lzma', or
'zstd'. '-L' is considered deprecated, but will probably never be removed.
All of the new features were documented in mkuzip.8; the page was also
cleaned up slightly.
Relnotes: yes
2019-08-13 23:32:56 +00:00
|
|
|
.Xr gzip 1
|
|
|
|
|
over the entire image.
|
|
|
|
|
However, it should be kept in mind that larger cluster sizes lead to higher
|
|
|
|
|
overhead in the
|
2004-09-10 20:17:31 +00:00
|
|
|
.Xr geom_uzip 4
|
|
|
|
|
class, as the class has to decompress the whole cluster even if
|
2006-03-17 20:48:10 +00:00
|
|
|
only a few bytes from that cluster have to be read.
|
2004-09-10 22:26:31 +00:00
|
|
|
.Pp
|
geom_uzip(4), mkuzip(8): Add Zstd image mode
The Zstd format bumps the CLOOP major number to 4 to avoid incompatibility
with older systems. Support in geom_uzip(4) is conditional on the ZSTDIO
kernel option, which is enabled in amd64 GENERIC, but not all in-tree
configurations.
mkuzip(8) was modified slightly to always initialize the nblocks + 1'th
offset in the CLOOP file format. Previously, it was only initialized in the
case where the final compressed block happened to be unaligned w.r.t.
DEV_BSIZE. The "Fake" last+1 block change in r298619 means that the final
compressed block's 'blen' was never correct unless the compressed uzip image
happened to be BSIZE-aligned. This happened in about 1 out of every 512
cases. The zlib and lzma decompressors are probably tolerant of extra trash
following the frame they were told to decode, but Zstd complains that the
input size is incorrect.
Correspondingly, geom_uzip(4) was modified slightly to avoid trashing the
nblocks + 1'th offset when it is known to be initialized to a good value.
This corrects the calculated final real cluster compressed length to match
that printed by mkuzip(8).
mkuzip(8) was refactored somewhat to reduce code duplication and increase
ease of adding other compression formats.
* Input block size validation was pulled out of individual compression
init routines into main().
* Init routines now validate a user-provided compression level or select
an algorithm-specific default, if none was provided.
* A new interface for calculating the maximal compressed size of an
incompressible input block was added for each driver. The generic code
uses it to validate against MAXPHYS as well as to allocate compression
result buffers in the generic code.
* Algorithm selection is now driven by a table lookup, to increase ease of
adding other formats in the future.
mkuzip(8) gained the ability to explicitly specify a compression level with
'-C'. The prior defaults -- 9 for zlib and 6 for lzma -- are maintained.
The new zstd default is 9, to match zlib.
Rather than select lzma or zlib with '-L' or its absense, respectively, a
new argument '-A <algorithm>' is provided to select 'zlib', 'lzma', or
'zstd'. '-L' is considered deprecated, but will probably never be removed.
All of the new features were documented in mkuzip.8; the page was also
cleaned up slightly.
Relnotes: yes
2019-08-13 23:32:56 +00:00
|
|
|
Additionally, the threshold at 16-32 kB where a larger cluster size does not
|
|
|
|
|
benefit overall compression ratio is an artifact of the
|
|
|
|
|
.Xr zlib 3
|
|
|
|
|
algorithm in particular.
|
|
|
|
|
.Ar Lzma
|
|
|
|
|
and
|
|
|
|
|
.Ar Zstd will continue to provide better compression ratios as cluster sizes
|
|
|
|
|
are increased, at high enough compression levels.
|
|
|
|
|
The same tradeoff continues to apply: reads in
|
|
|
|
|
.Xr geom_uzip 4
|
|
|
|
|
become more expensive the greater the cluster size.
|
|
|
|
|
.Pp
|
2006-09-29 15:20:48 +00:00
|
|
|
The
|
2004-09-10 22:26:31 +00:00
|
|
|
.Nm
|
2006-09-29 15:20:48 +00:00
|
|
|
utility
|
2006-03-17 20:48:10 +00:00
|
|
|
inserts a short shell script at the beginning of the generated image,
|
2004-09-10 22:26:31 +00:00
|
|
|
which makes it possible to
|
2004-09-11 18:39:01 +00:00
|
|
|
.Dq run
|
|
|
|
|
the image just like any other shell script.
|
2006-03-17 20:48:10 +00:00
|
|
|
The script tries to load the
|
2004-09-10 22:26:31 +00:00
|
|
|
.Xr geom_uzip 4
|
2006-03-17 20:48:10 +00:00
|
|
|
class if it is not loaded, configure the image as an
|
2004-09-10 22:26:31 +00:00
|
|
|
.Xr md 4
|
|
|
|
|
disk device using
|
2006-03-17 20:48:10 +00:00
|
|
|
.Xr mdconfig 8 ,
|
|
|
|
|
and automatically mount it using
|
2004-09-10 22:26:31 +00:00
|
|
|
.Xr mount_cd9660 8
|
2006-03-17 20:48:10 +00:00
|
|
|
on the mount point provided as the first argument to the script.
|
Improve mkuzip(8) and geom_uzip(4), merge in LZMA support from mkulzma(8)
and geom_uncompress(4):
1. mkuzip(8):
- Proper support for eliminating all-zero blocks when compressing an
image. This feature is already supported by the geom_uzip(4) module
and CLOOP format in general, so it's just a matter of making mkuzip(8)
match. It should be noted, however that this feature while it sounds
great, results in very slight improvement in the overall compression
ratio, since compressing default 16k all-zero block produces only 39
bytes compressed output block, which is 99.8% compression ratio. With
typical average compression ratio of amd64 binaries and data being
around 60-70% the difference between 99.8% and 100.0% is not that
great further diluted by the ratio of number of zero blocks in the
uncompressed image to the overall number of blocks being less than
0.5 (typically). However, this may be important from performance
standpoint, so that kernel are not spinning its wheels decompressing
those empty blocks every time this zero region is read. It could also
be important when you create huge image mostly filled with zero
blocks for testing purposes.
- New feature allowing to de-duplicate output image. It turns out that
if you twist CLOOP format a bit you can do that as well. And unlike
zero-blocks elimination, this gives a noticeable improvement in the
overall compression ratio, reducing output image by something like
3-4% on my test UFS2 3GB image consisting of full FreeBSD base system
plus some of the packages (openjdk, apache etc), about 2.3GB worth of
file data (800+MB compressed). The only caveat is that images created
with this feature "on" would not work on older versions of FeeBSDxi
kernel, hence it's turned off by default.
- provide options to control both features and document them in manual
page.
- merge in all relevant LZMA compression support from the mkulzma(8),
add new option to select between both.
- switch license from ad-hoc beerware into standard 2-clause BSD.
2. geom_uzip(4):
- implement support for de-duplicated images;
- optimize some code paths to handle "all-zero" blocks without reading
any compressed data;
- beef up manual page to explain that geom_uzip(4) is not limited only
to md(4) images. The compressed data can be written to the block
device and accessed directly via magic of GEOM(4) and devfs(4),
including to mount root fs from a compressed drive.
- convert debug log code from being compiled in conditionally into
being present all the time and provide two sysctls to turn it on or
off. Due to intended use of the module, it can be used in
environments where there may not be a luxury to put new kernel with
debug code enabled. Having those options handy allows debug issues
without as much problem by just having access to serial console or
network shell access to a box/appliance. The resulting additional
CPU cycles are just few int comparisons and branches, and those are
minuscule when compared to data decompression which is the main
feature of the module.
- hopefully improve robustness and resiliency of the geom_uzip(4) by
performing some of the data validation / range checking on the TOC
entries and rejecting to attach to an image if those checks fail.
- merge in all relevant LZMA decompression support from the
geom_uncompress(4), enable automatically when appropriate format is
indicated in the header.
- move compilation work into its own worker thread so that it does not
clog g_up. This allows multiple instances work in parallel utilizing
smp cores.
- document new knobs in the manual page.
Reviewed by: adrian
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D5333
2016-02-23 23:59:08 +00:00
|
|
|
.Pp
|
|
|
|
|
The de-duplication is a
|
|
|
|
|
.Fx
|
|
|
|
|
specific feature and while it does not require any changes to on-disk
|
|
|
|
|
compressed image format, however it did require some matching changes to the
|
|
|
|
|
.Xr geom_uzip 4
|
|
|
|
|
to handle resulting images correctly.
|
geom_uzip(4), mkuzip(8): Add Zstd image mode
The Zstd format bumps the CLOOP major number to 4 to avoid incompatibility
with older systems. Support in geom_uzip(4) is conditional on the ZSTDIO
kernel option, which is enabled in amd64 GENERIC, but not all in-tree
configurations.
mkuzip(8) was modified slightly to always initialize the nblocks + 1'th
offset in the CLOOP file format. Previously, it was only initialized in the
case where the final compressed block happened to be unaligned w.r.t.
DEV_BSIZE. The "Fake" last+1 block change in r298619 means that the final
compressed block's 'blen' was never correct unless the compressed uzip image
happened to be BSIZE-aligned. This happened in about 1 out of every 512
cases. The zlib and lzma decompressors are probably tolerant of extra trash
following the frame they were told to decode, but Zstd complains that the
input size is incorrect.
Correspondingly, geom_uzip(4) was modified slightly to avoid trashing the
nblocks + 1'th offset when it is known to be initialized to a good value.
This corrects the calculated final real cluster compressed length to match
that printed by mkuzip(8).
mkuzip(8) was refactored somewhat to reduce code duplication and increase
ease of adding other compression formats.
* Input block size validation was pulled out of individual compression
init routines into main().
* Init routines now validate a user-provided compression level or select
an algorithm-specific default, if none was provided.
* A new interface for calculating the maximal compressed size of an
incompressible input block was added for each driver. The generic code
uses it to validate against MAXPHYS as well as to allocate compression
result buffers in the generic code.
* Algorithm selection is now driven by a table lookup, to increase ease of
adding other formats in the future.
mkuzip(8) gained the ability to explicitly specify a compression level with
'-C'. The prior defaults -- 9 for zlib and 6 for lzma -- are maintained.
The new zstd default is 9, to match zlib.
Rather than select lzma or zlib with '-L' or its absense, respectively, a
new argument '-A <algorithm>' is provided to select 'zlib', 'lzma', or
'zstd'. '-L' is considered deprecated, but will probably never be removed.
All of the new features were documented in mkuzip.8; the page was also
cleaned up slightly.
Relnotes: yes
2019-08-13 23:32:56 +00:00
|
|
|
.Pp
|
|
|
|
|
To make use of
|
|
|
|
|
.Ar zstd
|
|
|
|
|
.Nm
|
|
|
|
|
images, the kernel must be configured with
|
|
|
|
|
.Cd ZSTDIO .
|
|
|
|
|
It is enabled by default in many
|
|
|
|
|
.Cd GENERIC
|
|
|
|
|
kernels provided as binary distributions by
|
|
|
|
|
.Fx .
|
|
|
|
|
The status on any particular system can be verified by checking
|
|
|
|
|
.Xr sysctl 8
|
|
|
|
|
.Dv kern.features.geom_uzip_zstd
|
|
|
|
|
for
|
|
|
|
|
.Dq 1 .
|
2005-01-18 13:43:56 +00:00
|
|
|
.Sh EXIT STATUS
|
|
|
|
|
.Ex -std
|
2004-09-10 20:17:31 +00:00
|
|
|
.Sh SEE ALSO
|
|
|
|
|
.Xr gzip 1 ,
|
Improve mkuzip(8) and geom_uzip(4), merge in LZMA support from mkulzma(8)
and geom_uncompress(4):
1. mkuzip(8):
- Proper support for eliminating all-zero blocks when compressing an
image. This feature is already supported by the geom_uzip(4) module
and CLOOP format in general, so it's just a matter of making mkuzip(8)
match. It should be noted, however that this feature while it sounds
great, results in very slight improvement in the overall compression
ratio, since compressing default 16k all-zero block produces only 39
bytes compressed output block, which is 99.8% compression ratio. With
typical average compression ratio of amd64 binaries and data being
around 60-70% the difference between 99.8% and 100.0% is not that
great further diluted by the ratio of number of zero blocks in the
uncompressed image to the overall number of blocks being less than
0.5 (typically). However, this may be important from performance
standpoint, so that kernel are not spinning its wheels decompressing
those empty blocks every time this zero region is read. It could also
be important when you create huge image mostly filled with zero
blocks for testing purposes.
- New feature allowing to de-duplicate output image. It turns out that
if you twist CLOOP format a bit you can do that as well. And unlike
zero-blocks elimination, this gives a noticeable improvement in the
overall compression ratio, reducing output image by something like
3-4% on my test UFS2 3GB image consisting of full FreeBSD base system
plus some of the packages (openjdk, apache etc), about 2.3GB worth of
file data (800+MB compressed). The only caveat is that images created
with this feature "on" would not work on older versions of FeeBSDxi
kernel, hence it's turned off by default.
- provide options to control both features and document them in manual
page.
- merge in all relevant LZMA compression support from the mkulzma(8),
add new option to select between both.
- switch license from ad-hoc beerware into standard 2-clause BSD.
2. geom_uzip(4):
- implement support for de-duplicated images;
- optimize some code paths to handle "all-zero" blocks without reading
any compressed data;
- beef up manual page to explain that geom_uzip(4) is not limited only
to md(4) images. The compressed data can be written to the block
device and accessed directly via magic of GEOM(4) and devfs(4),
including to mount root fs from a compressed drive.
- convert debug log code from being compiled in conditionally into
being present all the time and provide two sysctls to turn it on or
off. Due to intended use of the module, it can be used in
environments where there may not be a luxury to put new kernel with
debug code enabled. Having those options handy allows debug issues
without as much problem by just having access to serial console or
network shell access to a box/appliance. The resulting additional
CPU cycles are just few int comparisons and branches, and those are
minuscule when compared to data decompression which is the main
feature of the module.
- hopefully improve robustness and resiliency of the geom_uzip(4) by
performing some of the data validation / range checking on the TOC
entries and rejecting to attach to an image if those checks fail.
- merge in all relevant LZMA decompression support from the
geom_uncompress(4), enable automatically when appropriate format is
indicated in the header.
- move compilation work into its own worker thread so that it does not
clog g_up. This allows multiple instances work in parallel utilizing
smp cores.
- document new knobs in the manual page.
Reviewed by: adrian
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D5333
2016-02-23 23:59:08 +00:00
|
|
|
.Xr xz 1 ,
|
geom_uzip(4), mkuzip(8): Add Zstd image mode
The Zstd format bumps the CLOOP major number to 4 to avoid incompatibility
with older systems. Support in geom_uzip(4) is conditional on the ZSTDIO
kernel option, which is enabled in amd64 GENERIC, but not all in-tree
configurations.
mkuzip(8) was modified slightly to always initialize the nblocks + 1'th
offset in the CLOOP file format. Previously, it was only initialized in the
case where the final compressed block happened to be unaligned w.r.t.
DEV_BSIZE. The "Fake" last+1 block change in r298619 means that the final
compressed block's 'blen' was never correct unless the compressed uzip image
happened to be BSIZE-aligned. This happened in about 1 out of every 512
cases. The zlib and lzma decompressors are probably tolerant of extra trash
following the frame they were told to decode, but Zstd complains that the
input size is incorrect.
Correspondingly, geom_uzip(4) was modified slightly to avoid trashing the
nblocks + 1'th offset when it is known to be initialized to a good value.
This corrects the calculated final real cluster compressed length to match
that printed by mkuzip(8).
mkuzip(8) was refactored somewhat to reduce code duplication and increase
ease of adding other compression formats.
* Input block size validation was pulled out of individual compression
init routines into main().
* Init routines now validate a user-provided compression level or select
an algorithm-specific default, if none was provided.
* A new interface for calculating the maximal compressed size of an
incompressible input block was added for each driver. The generic code
uses it to validate against MAXPHYS as well as to allocate compression
result buffers in the generic code.
* Algorithm selection is now driven by a table lookup, to increase ease of
adding other formats in the future.
mkuzip(8) gained the ability to explicitly specify a compression level with
'-C'. The prior defaults -- 9 for zlib and 6 for lzma -- are maintained.
The new zstd default is 9, to match zlib.
Rather than select lzma or zlib with '-L' or its absense, respectively, a
new argument '-A <algorithm>' is provided to select 'zlib', 'lzma', or
'zstd'. '-L' is considered deprecated, but will probably never be removed.
All of the new features were documented in mkuzip.8; the page was also
cleaned up slightly.
Relnotes: yes
2019-08-13 23:32:56 +00:00
|
|
|
.Xr zstd 1 ,
|
2017-02-11 23:40:57 +00:00
|
|
|
.Xr zlib 3 ,
|
2004-09-10 22:26:31 +00:00
|
|
|
.Xr geom 4 ,
|
2004-09-11 18:39:01 +00:00
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.Xr geom_uzip 4 ,
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2004-09-10 22:26:31 +00:00
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.Xr md 4 ,
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.Xr mdconfig 8 ,
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2004-09-11 18:39:01 +00:00
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.Xr mount_cd9660 8
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2004-09-10 20:17:31 +00:00
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.Sh AUTHORS
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2014-06-23 08:23:05 +00:00
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|
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.An Maxim Sobolev Aq Mt sobomax@FreeBSD.org
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