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 -- Libvir-list mailing list Libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list