Re: Repair Metadata corruption detected at xfs_inode_buf_verify on CentOS 7 virtual machine

brian
2021-09-08T23:08:59Z

Here is an update of the error.  If something looks off, let me know and
I'll double check I transcribed correct.  Let me know if there is a way
to post a screenshot.

----------------------------------------------------------------------------

XFS (dm-2): Metadata corruption detected at
xfs_inode_buf_verify+0x14d/0x160 [xfs] xfs_inode block 0x1b5c1c0
xfs_inode_buf_verify
XFS (dm-2): Unmount and run xfs_repair
XFS (dm-2): First 128 bytes of corrupted metadata buffer:
ffffae6842564000: 16 49 77 8a 32 7e 72 52 14 bb 51 98 7c a5 2c 9a
.Iw.2~rR..Q.|.,.
ffffae6842564010: dd 28 4d 94 88 03 2b 8c 99 33 67 ca 6a d5 aa c9
.(M...+..3g.j...
ffffae6842564020: f8 f8 78 c7 90 fc f5 af 7f 95 03 07 0e 0c 4a 37
..x...........J7
ffffae6842564030: 7c f8 70 c7 09 14 c7 81 a5 a7 a7 cb a8 a8 28 b9
|.p...........(.
ffffae6842564040: 68 d1 a2 a0 73 f5 ae d5 73 94 23 3d 3d 5d 46 46
h...s...s.#--]FF
ffffae6842564050: 46 ca f9 f3 e7 3b 69 4c d3 94 6d db b6 75 14 3d
F....;iL..m..u.=
ffffae6842564060: 30 68 77 ec d8 e1 a4 d9 b7 6f 9f 0c 0b 0b 0b 32
)hw......o.....2
ffffae6842564070: 8e 9d 29 aa 03 4b 4c 4c 0c 52 66 29 a5 7c f4 d1
..)..KLL.Rf).|..
XFS (dm-2): metadata I/O error in “xlog_recov_do..(read#2)” at daddr
0x1b32 error 117

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My computer is an older CentOS 6 box (on my todo list to replace).  I
have an array of VirtualBox VMs.  All my data including VMs is in
/home/brian directory.  I run rsync to backup /home/brian directory to a
USB drive.  Rsync treats the files of the VM just like any other file.
I noticed that the VMs can get corrupted if I leave them running during
back up with rsync so I normally shut them down.  For this instance, I
didn't shut down the VM when I launched rsync.

@Dave
Regarding your image file question, I don't believe the above is an
image file.  Rsync copies file by file.  And I can navigate to the USB
like my internal hdd.

Regarding the freeze files system, no I did not freeze the guest.

Regarding the older backups, I just have the rsync backup on a USB
drive.  I've been working with a copy from the USB to try at get this
machine back, thus the unmodified USB rsync that was taken while the
machine was running exists.

While rsync was running, I had Selenium running web app tests in
Chrome.  All the data from my program was being written to a shared
folder.  Chrome has it's own internal cache that could be changing but
overall, I wouldn't expect the file system to be changing too much
especially the booting part.

My ultimate goal is to get to the data on this VM.  I've tried to mount
this .vdi file in another instance of CentOS but have not been
successful.  I may spin up an Ubuntu instance to try to get to the
data.  The data on this VM can be recreated but I prefer not to have to
redo the work.

Thank you for your help.

Brian

On 09/08/2021 05:39 PM, Dave Chinner wrote:
> On Wed, Sep 08, 2021 at 10:35:57AM -0400, brian wrote:
>> I have CentOS 7 Virtualbox virtual machine (VM) that gives the following
>> error on boot(removed parts replaced with …)
>> ----------------------------------------------------------------------------
>> XFS (dm-2): Metadata corruption detected at xfs_inode_buf_verify...
>> XFS (dm-2): unmount and run xfs_repair
>> XFS (dm-2): First 128 bytes of corrupted metadata buffer:
>> …
> You cut out the part of the error report that actually means
> something to us. Can you post the error message in full?
>
>> XFS (dm-2): metadata I/O error in “xlog_recov_do..(read#2)” at daddr 0x1b32
>> error 117
>> ----------------------------------------------------------------------------
>>
>> I tried entered emergency mode, entered password and tried:
>>     xfs_repair -L /dev/mapper/centos-root
>>
>> But I got the error:
>>     /dev/mapper/centos-root contains a mounted filesystem
>>     /dev/mapper/centos-root contains a mounted and writable filesystem
> $ man xfs_repair
> ....
> -d Repair dangerously. Allow xfs_repair to repair an XFS
> filesystem mounted read only. This is typically done on a
> root filesystem from single user mode, immediately followed
> by a reboot.
>
>> Next I booted from the Centos ISO then went
>>       troubleshooting → Rescue a CentOS system  → 1) Continue
>>
>> This fails.  I get lines of = marks.  When I left overnight, I had a blank
>> screen.  When I ALT+Tab to program-log and then back to main, I got a screen
>> of scrolling errors.
> Which typically happens if the filesystem full of inconsistencies
> and corruptions.
>
>> I nightly backup my data including this VM with rsync to a USB drive.  My
>> last backup was while the VM was running.  In Virtualbox and on my computers
>> drive, I deleted the VM using the virtualbox GUI.  I thought this would move
>> the VM to the trash but it permanently deleted the VM.  The problem I'm
>> having is with the backup VM from my USB drive.
> How did you do the backup? Was it an image file backup from the
> host, or a full filesystem rsync from inside the guest ?
>
>> How should I troubleshoot and fix this problem?  My main goal is to get my
>> data off the VM.  I also unsuccessful with mounting the .vdi file in another
>> computer.
> Sounds like you simply backed up the image file on the host?
>
> If so, did you freeze the filesystem in the guest (or the whole
> guest VM) while you did the backup? If the guest fs wasnt' frozen,
> and the VM was active while the backup was done as you say, then it
> is guaranteed that the image file that was copied will contain an
> inconsistent image of the filesystem. If there was lots of
> modifications occurring at the time of the copy being run, it will
> be full of corruptions and may well be completely unrecoverable.
>
> DO you have any older backups you can try to recover from?
>
> Cheers,
>
> Dave.