NAME
fstrim - discard unused blocks on a mounted filesystemSYNOPSIS
fstrim [-Aa] [-o offset] [-l length] [-m minimum-size] [-v mountpoint]DESCRIPTION
fstrim is used on a mounted filesystem to discard (or "trim") blocks which are not in use by the filesystem. This is useful for solid-state drives (SSDs) and thinly-provisioned storage.OPTIONS
The offset, length, and minimum-size arguments may be followed by the multiplicative suffixes KiB (=1024), MiB (=1024*1024), and so on for GiB, TiB, PiB, EiB, ZiB and YiB (the "iB" is optional, e.g., "K" has the same meaning as "KiB") or the suffixes KB (=1000), MB (=1000*1000), and so on for GB, TB, PB, EB, ZB and YB.Trim all mounted filesystems mentioned in
/etc/fstab on devices that support the discard operation. The root
filesystem is determined from kernel command line if missing in the file. The
other supplied options, like --offset, --length and
--minimum, are applied to all these devices. Errors from filesystems
that do not support the discard operation, read-only devices, autofs and
read-only filesystems are silently ignored. Filesystems with
"X-fstrim.notrim" mount option are skipped.
Trim all mounted filesystems on devices that
support the discard operation. The other supplied options, like
--offset, --length and --minimum, are applied to all
these devices. Errors from filesystems that do not support the discard
operation, read-only devices and read-only filesystems are silently
ignored.
This option does everything apart from
actually call FITRIM ioctl.
Byte offset in the filesystem from which to
begin searching for free blocks to discard. The default value is zero,
starting at the beginning of the filesystem.
The number of bytes (after the starting point)
to search for free blocks to discard. If the specified value extends past the
end of the filesystem, fstrim will stop at the filesystem size
boundary. The default value extends to the end of the filesystem.
Specifies a colon-separated list of files in
fstab or kernel mountinfo format. All missing or empty files are silently
ignored. The evaluation of the list stops after first non-empty file.
For example:
--listed-in /etc/fstab:/proc/self/mountinfo.
Filesystems with "X-fstrim.notrim" mount option in fstab are
skipped.
Minimum contiguous free range to discard, in
bytes. (This value is internally rounded up to a multiple of the filesystem
block size.) Free ranges smaller than this will be ignored and fstrim
will adjust the minimum if it’s smaller than the device’s
minimum, and report that (fstrim_range.minlen) back to userspace. By
increasing this value, the fstrim operation will complete more quickly
for filesystems with badly fragmented freespace, although not all blocks will
be discarded. The default value is zero, discarding every free block.
Verbose execution. With this option
fstrim will output the number of bytes passed from the filesystem down
the block stack to the device for potential discard. This number is a maximum
discard amount from the storage device’s perspective, because
FITRIM ioctl called repeated will keep sending the same sectors for
discard repeatedly.
fstrim will report the same potential discard bytes each time, but only
sectors which had been written to between the discards would actually be
discarded by the storage device. Further, the kernel block layer reserves the
right to adjust the discard ranges to fit raid stripe geometry, non-trim
capable devices in a LVM setup, etc. These reductions would not be reflected
in fstrim_range.len (the --length option).
Suppress error messages if trim operation
(ioctl) is unsupported. This option is meant to be used in systemd
service file or in cron(8) scripts to hide warnings that are result of
known problems, such as NTFS driver reporting Bad file descriptor when
device is mounted read-only, or lack of file system support for ioctl
FITRIM call. This option also cleans exit status when unsupported
filesystem specified on fstrim command line.
Display help text and exit.
Print version and exit.
EXIT STATUS
0success
failure
all failed
some filesystem discards have succeeded, some
failed
AUTHORS
Lukas <[email protected]>Czerner Karel <[email protected]>ZakSEE ALSO
blkdiscard(8), mount(8)REPORTING BUGS
For bug reports, use the issue tracker at <https://github.com/util-linux/util-linux/issues>.AVAILABILITY
The fstrim command is part of the util-linux package which can be downloaded from Linux Kernel Archive <https://www.kernel.org/pub/linux/utils/util-linux/>.2022-05-11 | util-linux 2.38.1 |