Hi,
Seems that such migration is currently broken, at least for
0.9.11|0.9.12, with 0.9.8 all works fine:
virsh migrate --live testvm qemu+tcp://towerbig/system
---snip---
2012-05-17 21:22:30.250+0000: 16926: debug :
qemuDriverCloseCallbackGet:605 : vm=testvm,
uuid=feb7ccb6-1087-8661-9284-62e3a1e9f44a, conn=(nil)
2012-05-17 21:22:30.250+0000: 16926: debug :
qemuDriverCloseCallbackGet:611 : cb=(nil)
2012-05-17 21:22:30.250+0000: 16926: error :
virStorageFileIsSharedFSType:1007 : Invalid relative path
'rbd/testvm-Vwu': Invalid argument
2012-05-17 21:22:30.250+0000: 16926: debug :
qemuDomainObjEndAsyncJob:955 : Stopping async job: migration out
2012-05-17 21:22:30.250+0000: 16926: debug : virDomainObjUnref:1645 :
obj=0x1c00cd0 refs=3
2012-05-17 21:22:30.250+0000: 16926: debug :
virDomainMigrateBegin3:6173 : xml (null)
2012-05-17 21:22:30.250+0000: 16926: debug : virDomainFree:2345 :
dom=0x1d7ee30, (VM: name=testvm,
uuid=feb7ccb6-1087-8661-9284-62e3a1e9f44a)
2012-05-17 21:22:30.250+0000: 16926: debug : virUnrefDomain:276 :
unref domain 0x1d7ee30 testvm 1
---snip---
Also there is a second point - libvirt doesn`t allow migration of VM
until all snapshots has been deleted, which is not necessary for
network filesystems, so it probably needs to be fixed. Thanks!