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

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@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@localhost vmimages]# [root@localhost vmimages]# virsh snapshot-list f17vm3-with-b Name Creation Time State ------------------------------------------------------------ snap1 2012-10-04 06:55:38 -0400 running [root@localhost vmimages]# #==================================================# [root@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@localhost vmimages]# #==================================================# [root@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@localhost vmimages]# #==================================================# [root@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@localhost qemu]# #==================================================# [root@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@localhost qemu]# #==================================================# -- /kashyap