f1e5596466
on devices using wear-leveling algorithms as a few weeks passed after review and discussion of trim(8) ceased and we still have no utility to perform the job. Reviewed by: hackers@ MFC after: 2 weeks
168 lines
4.3 KiB
Groff
168 lines
4.3 KiB
Groff
.\"
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.\" Copyright (c) 2019 Eugene Grosbein <eugen@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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.\"
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.\" $FreeBSD$
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.\"
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.Dd January 18, 2019
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.Dt TRIM 8
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.Os
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.Sh NAME
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.Nm trim
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.Nd erase device blocks that have no needed contents
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.Sh SYNOPSIS
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.Nm
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.Op Fl Nfqv
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.Fl [ [lo] Xo
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.Bk -words
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.Sm off
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.Ar offset
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.Op Cm K | k | M | m | G | g | T | t ]
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.Sm on
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.Xc
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.Ek
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.Bk -words
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.Op Fl r Ar rfile
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.Ek
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.Ar device ...
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.Sh DESCRIPTION
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The
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.Nm
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utility erases specified region of the device.
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It is mostly relevant for storage that implement trim (like flash based,
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or thinly provisioned storage).
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.Sy All erased data is lost.
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.Pp
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The following options are available:
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.Bl -tag -width indent
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.It Fl N
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Do not actually erase anything but show what it would do (dry run).
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Implies
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.Fl v .
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This is the default. Overrides
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.Fl f .
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.It Fl f
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Perform the operation. Overrides
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.Fl N .
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.It Fl l Xo
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.Sm off
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.Ar offset
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.Op Cm K | k | M | m | G | g | T | t
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.Sm on
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.Xc
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.It Fl o Xo
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.Sm off
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.Ar offset
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.Op Cm K | k | M | m | G | g | T | t
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.Sm on
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.Xc
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Specify the length
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.Fl l
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of the region to trim or its offset
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.Fl o
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from the beginning of the device.
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.Sy The whole device is erased by default
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unless one or both of these options are presented.
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.Pp
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The argument may be suffixed with one of
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.Cm K ,
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.Cm M ,
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.Cm G
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or
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.Cm T
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(either upper or lower case) to indicate a multiple of
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Kilobytes, Megabytes, Gigabytes or Terabytes
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respectively.
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.It Fl q
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Do not output anything except of possible error messages (quiet mode).
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Overrides
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.Fl v .
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.It Fl r Ar rfile
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Uses the length of given
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.Ar rfile
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as length of the region to erase.
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.Sy The whole device is erased by default.
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.It Fl v
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Show offset and length of actual region being erased, in bytes.
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.El
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.Pp
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Later options override previous ones.
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.Pp
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Note that actual success of the operation depends of underlying
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device driver such as
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.Xr ada 4 ,
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.Xr da 4
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and others.
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Refer to corresponding manual pages for detail on possible caveats
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in low level support for ATA TRIM or SCSI UNMAP commands.
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.Sh EXIT STATUS
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.Ex -std
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If the final erase operation fails for an argument, the
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.Nm
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utility returns exit code 1.
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It can also return one of the exit codes defined in
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.Xr sysexits 3 ,
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as follows:
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.Bl -tag -width ".Dv EX_UNAVAILABLE"
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.It Dv EX_USAGE
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The specified offset or length of the region is incorrect.
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.It Dv EX_OSERR
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There is no enough memory to proceed.
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.It Dv EX_NOINPUT
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The specified
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.Ar rfile
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cannot be opened (perhaps, it does not exist).
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.It Dv EX_IOERR
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The specified
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.Ar rfile
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cannot be examined for its size due to some system input/output error.
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.It Dv EX_DATAERR
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The specified
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.Ar rfile
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is not regular file, directory nor special device, so its size
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cannot be examined.
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.It Dv EX_UNAVAILABLE
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The specified
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.Ar rfile
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is special device file not supporting DIOCGMEDIASIZE
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.Xr ioctl 2
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(probably not a disk), so its size cannot be examined.
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.El
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.Sh SEE ALSO
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.Xr ada 4 ,
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.Xr da 4 ,
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.Xr ioctl 2 ,
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.Xr nda 4 ,
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.Xr sysexits 3
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.Sh HISTORY
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The
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.Nm
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utility first appeared in
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.Fx 12.1 .
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.Sh AUTHORS
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The
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.Nm
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utility was written by
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.An Eugene Grosbein Aq Mt eugen@FreeBSD.org .
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