[linux-lvm] Snapshot removal problem

[Nick Wright]

Hi all,


I don't seem to be able to remove snapshots unless I first deactivate
the snapshot target. Indeed, trying to do brings about a situation
where a reboot is required.

I run the command as follows:

~# lvremove /dev/VolGroup01/backup_vol_snap
Do you really want to remove active logical volume "backup_vol_snap"?
[y/n]: 
  
If I answer no, ok, I return to my prompt. If I answer yes, the
command sits there forever, cannot be killed, and I must reboot my PC
before I can run any further LVM commands. E.g., lvdisplay will block
when trying to display details about backup_vol and backup_vol_snap
but does display info about logical volumes inside a different volume
group. Any command operating on VolGroup01 will block indefinitely.

This is a Debian Sarge box, running a vanilla 2.6.17 kernel.

lvm packages:
ii  lvm-common     1.5.17         The Logical Volume Manager for Linux
ii  lvm2           2.01.04-5      The Linux Logical Volume Manager

ii  dmsetup        1.01.00-4      The Linux Kernel Device Mapper
ii  libdevmapper1. 1.01.00-4      The Linux Kernel Device Mapper

~# lvm version
  LVM version:     2.01.04 (2005-02-09)
  Library version: 1.01.00-ioctl (2005-01-17)
  Driver version:  4.6.0

I can deactivate the snapshot target first, remove the snapshot and
reactivate -- thats fine for now, but inconvenient:

# take backup lv offline
lvchange -an /dev/VolGroup01/backup_vol

#delete snapshot
lvremove /dev/VolGroup01/backup_vol_snap

#reactivate backup vol
lvchange -ay /dev/VolGroup01/backup_vol


Any ideas on this? 


Thanks.

Nick