fs corruption not detected by xfs_check or _repair

[Eric Sandeen]

Marco Maisenhelder wrote:
> Hi list,
> 
> I have a little bit of a problem after a catastrophic hardware failure
> (power supply went up in smoke and took half of my server with it -
> luckily only one of my raid5 disks though). My xfs data partition on my
> raid has some severe corruption that prevents me from accessing some
> files and directories on the partition. This is how the problem
> manifests itself:
> 
> *marco:/etc# ls -lrt /store/xfs_corruption/x/
> ls: cannot access /store/xfs_corruption/x/db.backup2: Invalid argument
> ls: cannot access /store/xfs_corruption/x/db.backup1: Invalid argument
> total 0
> ?????????? ? ? ? ?                ? db.backup2
> ?????????? ? ? ? ?                ? db.backup1
> 
> xfs_check does not report any errors. xfs_repair does not repair anything.
> 
> xfs_repair version 3.1.2
> xfs_check version 3.1.2
> System is Debian stable using a 2.6.26-2-amd64 kernel
> 
> *marco:/etc# xfs_info /store/
> meta-data=/dev/mapper/vgraid-rstore isize=256    agcount=48,
> agsize=11443904 blks
>          =                       sectsz=512   attr=2
> data     =                       bsize=4096   blocks=549307392, imaxpct=25
>          =                       sunit=64     swidth=192 blks
> naming   =version 2              bsize=4096
> log      =internal               bsize=4096   blocks=32768, version=2
>          =                       sectsz=512   sunit=64 blks, lazy-count=1
> realtime =none                   extsz=4096   blocks=0, rtextents=0
> 
> There's nothing in any of the system logs that would hint to the
> filesystem being corrupt.
> 
> I have done a metadump but after looking into it found that there's
> still sensitive information in there. I would be ok sharing it with
> individual developers but I can't put that on an open mailinglist.

You might be able to xfs_mdrestore, mount that, remove all but the
offending directory, re-metadump that, and put it out there?  Just a thought,
I haven't looked in further detail at your xfs_db adventures, sorry - maybe
there's enough info there but I'm swamped in other things ATM, so will leave
it to others, I hope.  :)

-Eric