Logical Volume Is Unreadable

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Hi all,

one of my lv has become completely unaccessible. Every read access results in a buffer io error:

Buffer I/O error on dev dm-13, logical block 0, async page read

this goes for every block in the lv. A ddrescue failed on every single block.

$ lvdisplay
— Logical volume –

5 thoughts on - Logical Volume Is Unreadable

  • Hello, Volker.

    Assuming that, at this point, everything that would have been running from this LV/FS is down, have you considered unmounting the filesystem and running a filesystem check against it?

    If it’s EXT2/3/4, you can run fsck against it, if it’s XFS, you can run xfs_repair against it.

  • That looks like a snapshot volume that became invalid because it was filled to capacity. Such a snapshot is lost forever. It si your responsibility to monitor snapshot usage to make sure it does not run out of space. The base volume, lv-vm-tviewer_vorigin, should still have its original content.

  • That’s it. Thanks for the information.

    How would I remove the only the snapshot but not the base volume? Will

    $ lvremove /dev/vg0/lv-vm-tviewer

    leave the base volume untouched?

  • That should do it. You will get one less warning if you deactivate that LV first:
    lvchange -an vg0/lv-vm-tviewer

    You will still get an overly alarmist warning that removing the snapshot LV will change the source LV. Don’t worry about it. The only “change” is that the source LV will no longer be flagged as a snapshot origin.

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