-.\" -*- nroff -*-
-.TH FSTRIM 8 "July 2014" "util-linux" "System Administration"
+.TH FSTRIM 8 "May 2019" "util-linux" "System Administration"
.SH NAME
fstrim \- discard unused blocks on a mounted filesystem
.SH SYNOPSIS
.B fstrim
-.RB [ \-a ]
+.RB [ \-Aa ]
.RB [ \-o
.IR offset ]
.RB [ \-l
Running
.B fstrim
frequently, or even using
-.BR "mount -o discard" ,
+.BR "mount \-o discard" ,
might negatively affect the lifetime of poor-quality SSD devices. For most
-desktop and server systems the sufficient trimming frequency is once a week.
+desktop and server systems a sufficient trimming frequency is once a week.
Note that not all
devices support a queued trim, so each trim command incurs a performance penalty
on whatever else might be trying to use the disk at the time.
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.
+.IP "\fB\-A, \-\-fstab\fP"
+Trim all mounted filesystems mentioned in \fI/etc/fstab\fR 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 \fB\-\-offset\fR, \fB\-\-length\fR and
+\fB-\-minimum\fR, 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.
.IP "\fB\-a, \-\-all\fP"
Trim all mounted filesystems on devices that support the discard operation.
The other supplied options, like \fB\-\-offset\fR, \fB\-\-length\fR and
\fB-\-minimum\fR, are applied to all these devices.
-Errors from filesystems that do not support the discard operation are silently
-ignored.
+Errors from filesystems that do not support the discard operation,
+read-only devices and read-only filesystems are silently ignored.
+.IP "\fB\-n, \-\-dry\-run\fP"
+This option does everything apart from actually call FITRIM ioctl.
.IP "\fB\-o, \-\-offset\fP \fIoffset\fP"
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
.B fstrim
will stop at the filesystem size boundary. The default value extends to
the end of the filesystem.
+.IP "\fB\-I, \-\-listed\-in\fP \fIlist\fP"
+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
+\fIlist\fP stops after first non-empty file. For example: \fB--listed-in /etc/fstab:/proc/self/mountinfo\fR.
.IP "\fB\-m, \-\-minimum\fP \fIminimum-size\fP"
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. By increasing this value, the fstrim operation
-will complete more quickly for filesystems with badly fragmented freespace,
-although not all blocks will be discarded. Default value is zero, discard
-every free block.
+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.
.IP "\fB\-v, \-\-verbose\fP"
Verbose execution. With this option
.B fstrim
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
-.B --length
+.B \-\-length
option).
.TP
+.B \-\-quiet\-unsupported
+Suppress error messages if trim operation (ioctl) is unsupported. This option
+is meant to be used in systemd service file or in cron scripts to hide warnings
+that are result of known problems,
+such as NTFS driver
+reporting
+.I Bad file descriptor
+when device is mounted read-only, or lack of file system support for ioctl
+FITRIM call.
+.TP
.BR \-V , " \-\-version"
Display version information and exit.
.TP
.BR \-h , " \-\-help"
Display help text and exit.
-.SH RETURN CODES
+.SH EXIT STATUS
.IP 0
success
.IP 1
some filesystem discards have succeeded, some failed
.PP
The command
-.B fstrim --all
+.B fstrim \-\-all
returns 0 (all succeeded), 32 (all failed) or 64 (some failed, some succeeded).
-.SH AUTHOR
+.SH AUTHORS
.nf
Lukas Czerner <lczerner@redhat.com>
Karel Zak <kzak@redhat.com>
.fi
.SH SEE ALSO
+.BR blkdiscard (8),
.BR mount (8)
.SH AVAILABILITY
The fstrim command is part of the util-linux package and is available from
-ftp://ftp.kernel.org/pub/linux/utils/util-linux/.
+https://www.kernel.org/pub/linux/utils/util-linux/.
projects / thirdparty / util-linux.git / blobdiff