1c85e6a35d
filesystem expands the inode to 256 bytes to make space for 64-bit block pointers. It also adds a file-creation time field, an ability to use jumbo blocks per inode to allow extent like pointer density, and space for extended attributes (up to twice the filesystem block size worth of attributes, e.g., on a 16K filesystem, there is space for 32K of attributes). UFS2 fully supports and runs existing UFS1 filesystems. New filesystems built using newfs can be built in either UFS1 or UFS2 format using the -O option. In this commit UFS1 is the default format, so if you want to build UFS2 format filesystems, you must specify -O 2. This default will be changed to UFS2 when UFS2 proves itself to be stable. In this commit the boot code for reading UFS2 filesystems is not compiled (see /sys/boot/common/ufsread.c) as there is insufficient space in the boot block. Once the size of the boot block is increased, this code can be defined. Things to note: the definition of SBSIZE has changed to SBLOCKSIZE. The header file <ufs/ufs/dinode.h> must be included before <ufs/ffs/fs.h> so as to get the definitions of ufs2_daddr_t and ufs_lbn_t. Still TODO: Verify that the first level bootstraps work for all the architectures. Convert the utility ffsinfo to understand UFS2 and test growfs. Add support for the extended attribute storage. Update soft updates to ensure integrity of extended attribute storage. Switch the current extended attribute interfaces to use the extended attribute storage. Add the extent like functionality (framework is there, but is currently never used). Sponsored by: DARPA & NAI Labs. Reviewed by: Poul-Henning Kamp <phk@freebsd.org>
173 lines
5.9 KiB
Groff
173 lines
5.9 KiB
Groff
.\" Copyright (c) 1983, 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)tunefs.8 8.2 (Berkeley) 12/11/93
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd May 18, 2002
|
|
.Dt TUNEFS 8
|
|
.Os
|
|
.Sh NAME
|
|
.Nm tunefs
|
|
.Nd tune up an existing filesystem
|
|
.Sh SYNOPSIS
|
|
.Nm
|
|
.Op Fl A
|
|
.Op Fl a Ar maxcontig
|
|
.Op Fl e Ar maxbpg
|
|
.Op Fl f Ar avgfilesize
|
|
.Op Fl m Ar minfree
|
|
.Bk -words
|
|
.Op Fl n Ar enable | disable
|
|
.Op Fl o Ar space | time
|
|
.Op Fl p
|
|
.Op Fl s Ar avgfpdir
|
|
.Ek
|
|
.Ar special | Ar filesystem
|
|
.Sh DESCRIPTION
|
|
.Nm Tunefs
|
|
is designed to change the dynamic parameters of a filesystem
|
|
which affect the layout policies.
|
|
The
|
|
.Nm
|
|
program cannot be run on an active filesystem.
|
|
To change an active filesystem,
|
|
you must either downgrade the filesystem to read-only
|
|
or unmount it.
|
|
.Pp
|
|
The parameters which are to be changed are indicated by the flags
|
|
given below:
|
|
.Bl -tag -width indent
|
|
.It Fl A
|
|
The filesystem has several backups of the super-block. Specifying
|
|
this option will cause all backups to be modified as well as the
|
|
primary super-block. This is potentially dangerous - use with caution.
|
|
.It Fl a Ar maxcontig
|
|
Specify the maximum number of contiguous blocks that will
|
|
be laid out before allowing a rotational delay.
|
|
The default value is 16.
|
|
.It Fl e Ar maxbpg
|
|
Indicate the maximum number of blocks any single file can
|
|
allocate out of a cylinder group before it is forced to begin
|
|
allocating blocks from another cylinder group.
|
|
Typically this value is set to about one quarter of the total blocks
|
|
in a cylinder group.
|
|
The intent is to prevent any single file from using up all the
|
|
blocks in a single cylinder group,
|
|
thus degrading access times for all files subsequently allocated
|
|
in that cylinder group.
|
|
The effect of this limit is to cause big files to do long seeks
|
|
more frequently than if they were allowed to allocate all the blocks
|
|
in a cylinder group before seeking elsewhere.
|
|
For filesystems with exclusively large files,
|
|
this parameter should be set higher.
|
|
.It Fl f Ar avgfilezsize
|
|
Specify the expected average file size.
|
|
.It Fl m Ar minfree
|
|
Specify the percentage of space held back
|
|
from normal users; the minimum free space threshold.
|
|
The default value used is 8%.
|
|
Note that lowering the threshold can adversely affect performance:
|
|
.Pp
|
|
.Bl -bullet
|
|
.It
|
|
Settings of 5% and less force space optimization to
|
|
always be used which will greatly increase the overhead for file
|
|
writes.
|
|
.It
|
|
The filesystem's ability to avoid fragmentation will be reduced
|
|
when the total free space, including the reserve, drops below 15%.
|
|
As free space approaches zero, throughput can degrade by up to a
|
|
factor of three over the performance obtained at a 10% threshold.
|
|
.El
|
|
.Pp
|
|
If the value is raised above the current usage level,
|
|
users will be unable to allocate files until enough files have
|
|
been deleted to get under the higher threshold.
|
|
.It Fl n Ar enable | disable
|
|
Turn on/off soft updates.
|
|
An unmounted filesystem is required.
|
|
.It Fl o Ar space | time
|
|
The filesystem can either try to minimize the time spent
|
|
allocating blocks, or it can attempt to minimize the space
|
|
fragmentation on the disk.
|
|
Optimization for space has much
|
|
higher overhead for file writes.
|
|
The kernel normally changes the preference automatically as
|
|
the percent fragmentation changes on the filesystem.
|
|
.It Fl p
|
|
Show a summary of what the current tunable settings
|
|
are on the selected filesystem. More detailed information can be
|
|
obtained from the
|
|
.Xr dumpfs 8
|
|
or
|
|
.Xr ffsinfo 8
|
|
programs.
|
|
.It Fl s Ar avgfpdir
|
|
Specify the expected number of files per directory.
|
|
.El
|
|
.Pp
|
|
At least one of the above flags is required.
|
|
.Sh FILES
|
|
.Bl -tag -width ".Pa /etc/fstab"
|
|
.It Pa /etc/fstab
|
|
read this to determine the device file for a
|
|
specified mount point.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr fs 5 ,
|
|
.Xr dumpfs 8 ,
|
|
.Xr ffsinfo 8 ,
|
|
.Xr newfs 8
|
|
.Rs
|
|
.%A M. McKusick
|
|
.%A W. Joy
|
|
.%A S. Leffler
|
|
.%A R. Fabry
|
|
.%T "A Fast File System for UNIX"
|
|
.%J "ACM Transactions on Computer Systems 2"
|
|
.%N 3
|
|
.%P pp 181-197
|
|
.%D August 1984
|
|
.%O "(reprinted in the BSD System Manager's Manual, SMM:5)"
|
|
.Re
|
|
.Sh BUGS
|
|
This program should work on active filesystems.
|
|
.\" Take this out and a Unix Daemon will dog your steps from now until
|
|
.\" the time_t's wrap around.
|
|
.Pp
|
|
You can tune a filesystem, but you can't tune a fish.
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
command appeared in
|
|
.Bx 4.2 .
|