lvremove hangs on removing snapshot

Hello,

When trying to remove a dm-snapshot device, I see lvremove freezing. A reboot is then needed to get the system in a usable state again.

I know that previous freezes/segfaults on removing a snapshot have been traced to a problem with kcopyd, but I am running linux 2.6.16.16 which should contain the fix for these problems. So it seems that my problem is different.

The freeze happens consistently, and even if the snapshot and/or real device have not been accessed. For example, I type:

# lvcreate --size 1G --snapshot --name homesnap vg0/home
# lvremove vg0/home
Are you sure ... ? Y
 [ lvremove now frozen ]

If a filesystem was mounted on the original vg0/home, any attempt to access the filesystem will freeze as well. Other than that, the system remains responsive.

After a reboot, I see that vg0/home and vg0/homesnap are both still present but set to inactive. I can then lvremove vg0/homesnap and lvchange vg0/home to reactivate it.

If I strace lvremove on its one-way trip, I see that it sends a few DM_SUSPEND ioctls, then freezes on a DM_TABLE_LOAD ioctl.

Am I doing something wrong with the snapshot, or is this still a bug? I seem to remember that I had it working correctly some time ago, but now it fails all the time.
My system is Debian 3.1, linux 2.6.16.16, lvm2 2.01.04.

Thanks,
Joris.

Upgrade userspace:
2.6.16+ requires 2.02.*

Alasdair

[email protected]

Yep, this seems to fix the problem. Thanks for your help.

Bye,
Joris.