[7/5] xfs_repair.8: document dirty log conditions
diff mbox

Message ID 20170112193444.GY14038@birch.djwong.org
State Accepted
Headers show

Commit Message

Darrick J. Wong Jan. 12, 2017, 7:34 p.m. UTC
Add a section describing what is a dirty log, why xfs_repair won't touch
such things, and what one can do to clear the condition and check the
filesystem.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 man/man8/xfs_repair.8 |   19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

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Comments

Eric Sandeen Jan. 12, 2017, 7:41 p.m. UTC | #1
On 1/12/17 1:34 PM, Darrick J. Wong wrote:
> Add a section describing what is a dirty log, why xfs_repair won't touch
> such things, and what one can do to clear the condition and check the
> filesystem.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Thanks, this seems fine.

<resists urge to nitpick> ;)
<reserves right to last-minute commit mods>  :)

Reviewed-by: Eric Sandeen <sandeen@redhat.com>

> ---
>  man/man8/xfs_repair.8 |   19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/man/man8/xfs_repair.8 b/man/man8/xfs_repair.8
> index 1b4d9e3..e4ca88e 100644
> --- a/man/man8/xfs_repair.8
> +++ b/man/man8/xfs_repair.8
> @@ -510,6 +510,25 @@ will return a status of 1 if filesystem corruption was detected and
>  0 if no filesystem corruption was detected.
>  .B xfs_repair
>  run without the \-n option will always return a status code of 0.
> +.SH DIRTY LOGS
> +Due to the design of the XFS log, a dirty log can only be replayed on a
> +machine having the same CPU architecture as the machine which was
> +writing to the log.
> +xfs_repair cannot replay a dirty log and will return a status code of 2
> +when it detects a dirty log.
> +.PP
> +In this situation, the log can be replayed by mounting and immediately
> +unmounting the filesystem on the same class of machine that crashed.
> +Please make sure that the machine's hardware is reliable before
> +replaying to avoid compounding the problems.
> +.PP
> +If mounting fails, the log can be erased by running xfs_repair with the
> +-L option.
> +All metadata updates in progress at the time of the crash will be lost,
> +which may cause significant filesystem damage.
> +This should
> +.B only
> +be used as a last resort.
>  .SH BUGS
>  The filesystem to be checked and repaired must have been
>  unmounted cleanly using normal system administration procedures
> 

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Patch
diff mbox

diff --git a/man/man8/xfs_repair.8 b/man/man8/xfs_repair.8
index 1b4d9e3..e4ca88e 100644
--- a/man/man8/xfs_repair.8
+++ b/man/man8/xfs_repair.8
@@ -510,6 +510,25 @@  will return a status of 1 if filesystem corruption was detected and
 0 if no filesystem corruption was detected.
 .B xfs_repair
 run without the \-n option will always return a status code of 0.
+.SH DIRTY LOGS
+Due to the design of the XFS log, a dirty log can only be replayed on a
+machine having the same CPU architecture as the machine which was
+writing to the log.
+xfs_repair cannot replay a dirty log and will return a status code of 2
+when it detects a dirty log.
+.PP
+In this situation, the log can be replayed by mounting and immediately
+unmounting the filesystem on the same class of machine that crashed.
+Please make sure that the machine's hardware is reliable before
+replaying to avoid compounding the problems.
+.PP
+If mounting fails, the log can be erased by running xfs_repair with the
+-L option.
+All metadata updates in progress at the time of the crash will be lost,
+which may cause significant filesystem damage.
+This should
+.B only
+be used as a last resort.
 .SH BUGS
 The filesystem to be checked and repaired must have been
 unmounted cleanly using normal system administration procedures