btrfs-progs/Documentation/btrfs-scrub.txt
Gui Hecheng a2e2c295d9 btrfs-progs: correct manpage option description for scrub
The -f option of scrub means to
    "force starting new scrub even if a scrub is already running"
*not*
    "force to check whether scrub has started or resumed in userspace"
as described originally.

So replace the orignal description in the manpage and code.

Also, add description of the potential failure as follows
    "If a scrub is already running, it fails."

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: David Sterba <dsterba@suse.cz>
2014-08-22 15:07:01 +02:00

97 lines
2.7 KiB
Plaintext

btrfs-scrub(8)
==============
NAME
----
btrfs-scrub - scrub btrfs filesystem
SYNOPSIS
--------
*btrfs scrub* <subcommand> <args>
DESCRIPTION
-----------
*btrfs scrub* is used to scrub a btrfs filesystem, which will reading all data
from all disks and verifying checksums.
SUBCOMMAND
----------
*start* [-BdqrRf] [-c <ioprio_class> -n <ioprio_classdata>] <path>|<device>::
Start a scrub on all devices of the filesystem identified by <path> or on
a single <device>. If a scrub is already running, the new one fails.
+
Without options, scrub is started as a background process.
Progress can be obtained with the *scrub status* command. Scrubbing
involves reading all data from all disks and verifying checksums. Errors are
corrected along the way if possible.
+
The default IO priority of scrub is the idle class. The priority can be
configured similar to the `ionice`(1) syntax using '-c' and '-n' options.
+
`Options`
+
-B::::
Do not background and print scrub statistics when finished.
-d::::
Print separate statistics for each device of the filesystem (-B only).
-q::::
Quiet. Omit error messages and statistics.
-r::::
Read only mode. Do not attempt to correct anything.
-R::::
Raw print mode. Print full data instead of summary.
-c <ioprio_class>::::
Set IO priority class (see
ionice (1)
manpage).
-n <ioprio_classdata>::::
Set IO priority classdata (see `ionice`(1) manpage).
-f::::
Force starting new scrub even if a scrub is already running.
This is useful when scrub stat record file is damaged.
*cancel* <path>|<device>::
If a scrub is running on the filesystem identified by <path>, cancel it.
+
Progress is saved in the scrub progress file and scrubbing can be resumed later
using the scrub resume command.
If a <device> is given, the corresponding filesystem is found and
scrub cancel behaves as if it was called on that filesystem.
*resume* [-BdqrR] [-c <ioprio_class> -n <ioprio_classdata>] <path>|<device>::
Resume a canceled or interrupted scrub cycle on the filesystem identified by
<path> or on a given <device>.
+
Does not start a new scrub if the last scrub finished successfully.
+
`Options`
+
see *scrub start*.
*status* [-d] <path>|<device>::
Show status of a running scrub for the filesystem identified by <path> or
for the specified <device>.
+
If no scrub is running, show statistics of the last finished or canceled scrub
for that filesystem or device.
+
`Options`
+
-d::::
Print separate statistics for each device of the filesystem.
EXIT STATUS
-----------
*btrfs scrub* returns a zero exist status if it succeeds. Non zero is
returned in case of failure.
AVAILABILITY
------------
*btrfs* is part of btrfs-progs.
Please refer to the btrfs wiki http://btrfs.wiki.kernel.org for
further details.
SEE ALSO
--------
`mkfs.btrfs`(8),