Re: [libvirt-users] Live snapshot merging (qemu 2.0)

On 04/22/2014 01:47 AM, Thomas Stein wrote: > Hello. > > The Changelog of qemu-2.0.0 mentioned "Live snapshot merging". Someone > has an idea what could be ment by this? I'm asking because i'm still > struggling with finding a reliable backup solution for running kvm > machines. Blockcopy is my current solution. "Live snapshot merging" means going from a backing chain of "base <- img" to "base" by merging the contents of img into base. Libvirt does not yet support this action, but we are getting closer with our work on tracking the entire backing chain in domain XML. Current libvirt is able to support some chain shortening operations with older qemu: libvirt can do snapshot merging of any backing file (taking "base <- snap1 <- snap2" to "base <- snap2" by committing snap1 into base), as well as pulling content into the active layer (going from "base <- snap1 <- snap2" to "base <- snap2" by pulling snap1 into snap2). And as you mentioned, using blockcopy also allows libvirt to pivot to a new shorter backing chain.