[libvirt] virsh migrate with libvirt-0.5.1: failed to start listening VM
Hello, I was trying to migrate a KVM/QEMU VM running on a Fedora 10 host to another F10 host. Both machines have identical architectures (x86_64) and are running identical versions of libvirt and KVM (libvirt-0.5.1-2.fc10.x86_64, kvm-74-10.fc10.x86_64). However, the migration fails: # virsh migrate jhrozek-f11-minimal qemu+ssh://someothersystem.example.com/system libvir: QEMU error : operation failed: failed to start listening VM On the target host, the logfile /var/log/libvirt/qemu/jhrozek-f11-minimal.log says: qemu: could not open disk image /var/lib/libvirt/images/jhrozek-f11-minimal.img Which seems rather odd, isn't libvirt supposed to copy the image file? Is this supposed to work? Is there any way to debug the problem? I skimmed through RH Bugzilla and googled a bit but haven't found much clue. Help is appreciated, Jakub
On 07/14/2009 10:11 AM, Jakub Hrozek wrote:
Hello, I was trying to migrate a KVM/QEMU VM running on a Fedora 10 host to another F10 host. Both machines have identical architectures (x86_64) and are running identical versions of libvirt and KVM (libvirt-0.5.1-2.fc10.x86_64, kvm-74-10.fc10.x86_64). However, the migration fails:
# virsh migrate jhrozek-f11-minimal qemu+ssh://someothersystem.example.com/system libvir: QEMU error : operation failed: failed to start listening VM
On the target host, the logfile /var/log/libvirt/qemu/jhrozek-f11-minimal.log says: qemu: could not open disk image /var/lib/libvirt/images/jhrozek-f11-minimal.img
Which seems rather odd, isn't libvirt supposed to copy the image file?
Is this supposed to work? Is there any way to debug the problem? I skimmed through RH Bugzilla and googled a bit but haven't found much clue.
You're supposed to have /var/lib/libvirt/images mounted via shared storage (nfs/cifs/etc) on both machines. -- Scott Baker - Canby Telcom System Administrator - RHCE - 503.266.8253
Scott Baker wrote:
You're supposed to have /var/lib/libvirt/images mounted via shared storage (nfs/cifs/etc) on both machines.
I've heard of folks having trouble doing live migration over NFS -- something with stronger concurrency guarantees (GFS, a shared iSCSI or FC mount [possibly with cLVM to partition it up], etc) is likely to be a safer bet. (Indeed, looking at the documented preferred environment for VMware's VMotion is probably a good guideline for anything that's going to be trusted with real production usage -- a separate bonded pair of NICs on each host, connected to a dedicated network for communication with the SAN hosting the backing store).
On Tue, Jul 14, 2009 at 01:13:03PM -0500, Charles Duffy wrote:
Scott Baker wrote:
You're supposed to have /var/lib/libvirt/images mounted via shared storage (nfs/cifs/etc) on both machines.
I've heard of folks having trouble doing live migration over NFS -- something with stronger concurrency guarantees (GFS, a shared iSCSI or FC mount [possibly with cLVM to partition it up], etc) is likely to be a safer bet.
(Indeed, looking at the documented preferred environment for VMware's VMotion is probably a good guideline for anything that's going to be trusted with real production usage -- a separate bonded pair of NICs on each host, connected to a dedicated network for communication with the SAN hosting the backing store).
A method I'm going to be trying out very shortly is using DRBD in dual-primary mode. DRBD will keep LVM volumes (block devices) for each VM in sync between two nodes. Upon migration, writes will cease on node A and when ready, begin on node B. You won't have concurrent writes, so it will be safe to use DRBD directly without a clustering FS on top (GFS, OCFS2, etc...). DRBD has scripts for Xen that take care of the details for you. Haven't seen the same for KVM/QEMU yet, but I imagine it would be pretty similar. -- Garry Dolley ARP Networks, Inc. | http://www.arpnetworks.com | (818) 206-0181 Data center, VPS, and IP Transit solutions Member Los Angeles County REACT, Unit 336 | WQGK336 Blog http://scie.nti.st
participants (4)
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Charles Duffy -
Garry Dolley -
Jakub Hrozek -
Scott Baker