Safe way to fsck XFS fast clone-enabled partitions?

[cosmik]

Just trying to be on the safe side here. Got a physical debian 11 box serving as the backup repository for our VMWare-based VBR 11 setup. We'd like to fsck the XFS partition that hosts the backups. Fast clone was created as per https://helpcenter.veeam.com/archive/ba ... oning.html which include enabling XFS reflink.

Mount options (using multipathing to access some iSCSI-provided block storage):

Code: Select all

/dev/mapper/mpatha-part1 on /mnt/veeam1 type xfs (rw,relatime,attr2,inode64,logbufs=8,logbsize=32k,noquota,_netdev)

We would like to check and safely repair the file system. Stressing "safely" here, since I am not aware of whether the bundled xfs utilities like xfs_repair behave with reflink enabled and such; I'm afraid that perhaps doing a check and repair I might end up losing data. Is it safe and if so, which xfs_repair syntax would you use?

Which way would you recommend checking the file system itself?

PS: weekly health checks on the veeam backups are made, so far no issues at all.

[david.domask]

Hi Michael,

https://linux.die.net/man/8/xfs_check
https://linux.die.net/man/8/xfs_repair

As far as I'm aware, xfs_check and xfs_repair are intended to check and maintain XFS and they are reflink aware; in fact, as I get it from this man page, fsck.xfs will just return 0 in all situations unless you run it with special flags.

I'm not sure that there can be a guaranteed "safe" repair as I think there is always a chance it will need a lossy repair and it also depends on the flags you have; xfs_check should be enough to tell _if the issue is related to XFS itself or if it's elsewhere, and both xfs_check and xfs_repair will likely abort if they hit an actual hardware issue (bad block).

[cosmik]

Hey David,

thanks for the heads up. I was mainly interested to check whether the use of reflinks would prohibit using xfs_check/_repair: although I've read Veaam-with-XFS-related articles, I have not stumbled upon any ones that additionally mention both reflinks as well as xfs_check/_repair...