How do I unlock and/or remove a locked volume?

[Derek Dongray <derek@inverchapel.me.uk>]

I recently decided to move a volume group off of a mixed device (SATA+USB) md raid mirror after encountering the "bio too big" bug (which apparently is likely to cause data corruption, but is classified as WONTFIX! See https://bugzilla.redhat.com/show_bug.cgi?id=498162 or http://lmgtfy.com/?q=bio+too+big+wontfix).

 

The sequence started to use was:

 

1. Fail USB drive and remove from the raid mirror (mdadm).

2. Repartition USB drive (parted).

3. Create Physical Volume on USB drive and add to Volume Group (lvm pvcreate & vgextend).

4. Move Volume Group off of raid mirror (lvm pvmove).

5. Remove raid mirror from Volume Group and stop if being a Physical Volume (lvm vgreduce & pvremove).

6. Stop raid mirror (mdadm).

7. Repartiton SATA drive (parted).

8. Create new SATA-based Physical Volume and add to Volume Group (lvm pvcreate & vgextend).

9. Move volume group off USB-based Physical Volume (pvmove).

It was at this point (after a few hours) that the sysem 'hung' and was totally unresponsive. After powering down and rebooting, I attempted to abort the pvmove (pvmove --abort) but the system locked up again and I rebooted a second time. This time, the abort appeared to succeed, but when I started the pvmove againb I got a message about ignoring the locked volume 'pvmove0'. I proceeded with the remaining step:

 

10. Remove USB-based Physical Volume from the Volume Group and stop it being a Physical Volume (lvm vgreduce & pvremove)

 

The system appears to be running OK, but there is a zero-length, locked Logical Volume which I can't remove.

 

# lvs -a raid/pvmove0

  LV        VG   Attr   LSize Origin Snap%  Move Log Copy%  Convert

  [pvmove0] raid p-C---    0

 

# lvdisplay -a -v raid/pvmove0

    Using logical volume(s) on command line

  --- Logical volume ---

  LV Name                /dev/raid/pvmove0

  VG Name                raid

  LV UUID                2aWJ0g-B5P8-6bAz-zKlk-f4dQ-nwn8-80n12v

  LV Write Access        read/write

  LV Status              NOT available

  LV Size                0

  Current LE             0

  Segments               0

  Allocation             contiguous

  Read ahead sectors     auto

 

# tail -n11 /etc/lvm/backup/raid

                pvmove0 {

                        id = "2aWJ0g-B5P8-6bAz-zKlk-f4dQ-nwn8-80n12v"

                        status = ["READ", "WRITE", "PVMOVE", "LOCKED"]

                        flags = []

                        allocation_policy = "contiguous"

                        segment_count = 0

                }

        }

}

 

The volume is locked (as shown from the backup information output) so "lvremove --force raid/pvmove0"  simply complains "Can't remove locked LV pvmove0", but "pvmove --abort" (which would normally unlock this) does nothing because no pvmove is in progress.

 

So the question (as in the subject) is how do I unlock and/or remove a locked volume?

 

Thanks.

--

Derek.