Bugzilla – Bug 581590
lvm2 lvremove on snapshots works only sometimes
Last modified: 2010-09-26 06:39:11 UTC
User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.7) Gecko/20091222 SUSE/3.5.7-1.1.1 Firefox/3.5.7 while trying to remove a lvm2 snapshot it works sometimes, and sometimes not. Probably related to bug #556177 Reproducible: Sometimes Steps to Reproduce: 1. create lvcreate -s -L 5g -n test-snap /dev/vg_system/testvol (shows actually bug #556177 ) 2. check lvs |grep test-snap test-snap vg_system swi-a- 5.00G encrypted 0.00 lvdisplay /dev/vg_system/test-snap --- Logical volume --- LV Name /dev/vg_system/test-snap VG Name vg_system LV UUID 7Mk7e9-Qifn-WBS0-jA0G-z8AF-0H6g-gyUXdS LV Write Access read/write LV snapshot status active destination for /dev/vg_system/encrypted LV Status available # open 0 LV Size 32.00 GB Current LE 8192 COW-table size 5.00 GB COW-table LE 1280 Allocated to snapshot 0.00% Snapshot chunk size 4.00 KB Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:25 3. try to remove willie:~ # lvremove /dev/vg_system/test-snap Can't remove open logical volume "test-snap" willie:~ # lvremove /dev/vg_system/test-snap Can't remove open logical volume "test-snap" willie:~ # lvremove /dev/vg_system/test-snap Can't remove open logical volume "test-snap" willie:~ # lvremove /dev/vg_system/test-snap Can't remove open logical volume "test-snap" willie:~ # lvremove /dev/vg_system/test-snap Can't remove open logical volume "test-snap" willie:~ # lvremove /dev/vg_system/test-snap Can't remove open logical volume "test-snap" willie:~ # lvremove /dev/vg_system/test-snap Can't remove open logical volume "test-snap" willie:~ # lvremove /dev/vg_system/test-snap Can't remove open logical volume "test-snap" willie:~ # lvremove /dev/vg_system/test-snap Do you really want to remove active logical volume "test-snap"? [y/n]: y Logical volume "test-snap" successfully removed
Hi, same behaviour on OpenSUSE 11.3. (We didn't use 11.2. The error didn't occur in 11.1) We use snapshots to backup Xen-DomU's, so a patch would be desirable.
(In reply to comment #1) > Hi, > > same behaviour on OpenSUSE 11.3. (We didn't use 11.2. The error didn't occur in > 11.1) > We use snapshots to backup Xen-DomU's, so a patch would be desirable. Hi, I tried once to reproduce this on my machine, but failed. Could you provide me a step-by-step instruction on how to reproduce this ? Thanks.
Hi, thanks for help. I also tried to reproduce the error in a test environment, but this fails. In our productive environment the error occur unsteady. Since last week we use 11.3 on one server. The migration of other servers is in planning. We do the following: We have some physical server with Xen paravirtualized machines. These DomUs have partitions mounted like this: disk = [ 'phy:/dev/system/helios-dns_root,hda1,w', 'phy:/dev/system/helios-dns_swap,hdb1,w'] We backup the DomUs with the following procedure: 1. Shutdown the DomU xm shutdown -w ${DomU} 2. Create a snapshot lvcreate --snapshot --size 2000M --name ${Partition}.backup ${Partition} 3. Start the DomU xm start ${DomU} 4. Mount the snapshot 5. Create a tar archive of the mounted snapshot 6. Remove the snapshot lvremove -f ${Partition}.backup Since yesterday our backup script use a workaround (he tries to remove the snapshot up to 20 times :-). I will do some more testing and will wait until we migrate the other servers. Maybe the error depends on the server. If i have new informations, i will send a comment... regards Stefan
It depends from the server. I can reproduce the error only on one of two servers. Redhat has the same problem: https://bugzilla.redhat.com/show_bug.cgi?id=577798 When i stop boot.udev the problem doesn't occur.
Hi Stefan, This is very helpful info. Could you try to """ grep -r watch /etc/udev/rules.d/ /lib/udev/rules.d/ """ and see if there's a 80-udisks.rules ? If yes, could you delete it and retest ? Thanks. (In reply to comment #4) > It depends from the server. I can reproduce the error only on one of two > servers. > > Redhat has the same problem: https://bugzilla.redhat.com/show_bug.cgi?id=577798 > > When i stop boot.udev the problem doesn't occur.
Hi Wei Hu, i found the file /lib/udev/rules.d/80-udisks.rules. If i move it away and restart /etc/init.d/boot.udev , the error occurs anyway. If i move some other rules (1*) away, then lvcreate hangs. regards Stefan
(In reply to comment #6) > Hi Wei Hu, > > i found the file /lib/udev/rules.d/80-udisks.rules. > If i move it away and restart /etc/init.d/boot.udev , the error occurs anyway. Can you move the 80-udisks.rules to where it was, and comment out following line """ KERNEL=="dm-*", OPTIONS+="watch" """ I see someone reports that worked for them. > If i move some other rules (1*) away, then lvcreate hangs. 10-dm.rules 11-dm-lvm.rules 13-dm-disk.rules These 3 files are critical for lvm2 to working properly on 11.3 You should not remove any of them. Thanks
No change in behaviour.
(In reply to comment #9) > No change in behaviour. So, by running """ grep -r watch /etc/udev/rules.d/ /lib/udev/rules.d/ """ Do you find any other rules watching on device-mapper devices ?
keto-0:~ # grep -r watch /etc/udev/rules.d/ /lib/udev/rules.d/ /lib/udev/rules.d/80-udisks.rules:KERNEL=="dm-*", OPTIONS+="watch" /lib/udev/rules.d/60-persistent-storage.rules:# watch for future changes /lib/udev/rules.d/60-persistent-storage.rules:KERNEL!="sr*", OPTIONS+="watch" /lib/udev/rules.d/13-dm-disk.rules:OPTIONS+="watch"
if i comment out the lines in 80-udisks.rules and 13-dm-disk.rules, then the error doesn't occur. :-) Is this a possible workaround?
(In reply to comment #12) > if i comment out the lines in 80-udisks.rules and 13-dm-disk.rules, then the > error doesn't occur. :-) > > Is this a possible workaround? Good to know ;) Yes, I think this can be a workaround. It's always a problem for device mapper to interact with udev watch. We are going to follow upstream to resolve this issue. Thanks for testing this.