[libvirt] with latest libvirt(from git) on F18, time to take internal snapshot increases as snapshot count rises

[Kashyap Chamarthy]

Hi,

the below three internal snapshots were taken when the guest is running 'live'. Any hints
on why the time to take snapshots keep increasing ?
If you notice, the 2nd and 3rd internal snaphtots took more than 4 minutes each (note:
there is no noticeable content change from snap1 )

#==================================================#
[root at localhost vmimages]# time virsh snapshot-create-as f17vm3-with-b snap1
snap1-f17vm3-desc
Domain snapshot snap1 created

real	0m57.734s
user	0m0.009s
sys	0m0.024s
[root at localhost vmimages]#
[root at localhost vmimages]# virsh snapshot-list f17vm3-with-b
 Name                 Creation Time             State
------------------------------------------------------------
 snap1                2012-10-04 06:55:38 -0400 running

[root at localhost vmimages]#
#==================================================#
[root at localhost vmimages]# time virsh snapshot-create-as f17vm3-with-b snap2
snap2-f17vm3-desc
Domain snapshot snap2 created

real	4m19.126s
user	0m0.020s
sys	0m0.030s
[root at localhost vmimages]#
#==================================================#
[root at localhost vmimages]# time virsh snapshot-create-as f17vm3-with-b snap3
snap3-f17vm3-desc
Domain snapshot snap3 created

real	4m45.053s
user	0m0.013s
sys	0m0.032s
[root at localhost vmimages]#
#==================================================#
[root at localhost qemu]# qemu-img info /home/kashyap/vmimages/f17vm3-with-b.qcow2
image: /home/kashyap/vmimages/f17vm3-with-b.qcow2
file format: qcow2
virtual size: 5.0G (5368709120 bytes)
disk size: 755M
cluster_size: 65536
backing file: /home/kashyap/vmimages/base-f17.qcow2
Snapshot list:
ID        TAG                 VM SIZE                DATE       VM CLOCK
1         snap1                  232M 2012-10-04 06:55:38   19:58:19.804
2         snap2                  247M 2012-10-04 07:03:09   20:04:53.360
3         snap3                  244M 2012-10-04 07:08:23   20:05:48.889
4         snap4                     0 2012-10-04 08:51:16   00:00:00.000
5         snap5                     0 2012-10-04 08:53:04   00:00:00.000
[root at localhost qemu]#
#==================================================#
[root at localhost qemu]# virsh snapshot-list f17vm3-with-b
 Name                 Creation Time             State
------------------------------------------------------------
 snap1                2012-10-04 06:55:38 -0400 running
 snap2                2012-10-04 07:03:08 -0400 running
 snap3                2012-10-04 07:08:23 -0400 running
 snap4                2012-10-04 08:51:16 -0400 shutoff
 snap5                2012-10-04 08:53:04 -0400 shutoff

[root at localhost qemu]#

#==================================================#

-- 
/kashyap