[CentOS] EL7: Detecting FS errors on XFS while mounted

Fri Nov 20 23:18:38 UTC 2015
John R Pierce <pierce at hogranch.com>

On 11/20/2015 3:02 PM, Benjamin Smith wrote:
> Is there a way of checking an XFS filesystem for clean/dirty status while
> mounted?
> One of the checks we've long performed is an FS-level error check. This is
> *not a full-on fsck*, this is "asking the file system if it noted any
> problems". This is done while the file system is mounted and "hot". For
> example, here's how we'd check an ext* partition:
> # debugfs -R "show_super_stats -h" /dev/md127  | grep -i "Filesystem state"
> We'd look for "Filesystem state: clean" (or something else if not clean).
> ZFS also allows for a "hot & mounted" check for dirty file system:
> # zpool status
> So far, I've been unsuccessful in finding an equivalent for XFS.

xfs_check can only be run on a unmounted file system.      if XFS is 
mounted, its working.    if there have been any minor errors it would 
have repaired them on the fly, if there were serious errors, it would 
have barfed and gone read-only, with kernel errors logged in dmesg or 

zpool status is more reporting on the state of the volume manager side 
of zpool, whihc is checksumming data blocks as they are written and 
confirming as they are read.   if you're using md raid, you can query 
the status of the underlying volume iwth mdadm -Q /dev/mdXXX (or -D for 
more info).

john r pierce, recycling bits in santa cruz