On Thu, Jan 21, 2021 at 13:31:03 +0300, Andrey Fokin wrote: > Thanks Peter! > But is possible change XML configuration towards will be possible to do > full (push) backup? Yes, I've included links to the documentation to do so in my previous reply, so I'd suggest you follow it. See ... > On Wed, Jan 20, 2021 at 9:08 PM Peter Krempa <pkrempa@xxxxxxxxxx> wrote: > > > On Wed, Jan 20, 2021 at 20:49:49 +0300, Andrey Fokin wrote: > > > Colleagues, could you please advise what a problem could be in XML file > > in > > > case of: > > > virsh backup-begin lubuntu2 ./backup.xml > > > > > > where backup.xml - > > > <domainbackup> > > > <disk name='/var/lib/libvirt/images/lubuntu2.qcow2' type='file'> > > > <target file='$PWD/scratch1.img'/> > > > <driver type='raw'/> > > > </disk> > > > <disk name='/var/lib/libvirt/images/lubuntu2-1.qcow2' type='file'> > > > <target file='$PWD/scratch2.img'/> > > > <driver type='raw'/> > > > </disk> > > > </domainbackup> > > > > snip ... > > > > You forgot to add what you are observing, but I presume: > > > > 'operation unsupported: incremental backup is not supported yet' > > > > Unfortunately it's what it says on the tin. The implementation of the > > incremental backup code is not finished yet, thus the feature is > > disabled. > > > > If you want to test-drive incremental backup APIs, you can enable the > > experimental feature by using the XML documented in: > > > > https://libvirt.org/drvqemu.html#xmlnsfeatures ... here. I specifically avoided giving exact steps so that you read the documentation including the description of caveats of enabling this _experimental_ feature. So please make sure to read it. This is NOT meant for production use. Anyways: You need to add the 'qemu' namespace to your domain XML: <domain type='kvm' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'> And force-on the incremental backup capability: <qemu:capabilities> <qemu:add capability='incremental-backup'/> </qemu:capabilities> This enables backups, but as I've wrote previously ... > > > > to enable a feature named 'incremental-backup'. Please make sure to read > > the caveats of doing so thoroughly. .. observe the following: > > I also advise not to combine incremental backups with snapshots > > (virDomainSnapshot* APIs) and blockjobs (virDomainBlock* APIs) as that > > will not work properly without a patch enabling also experimental qemu > > features. If you use them, backups will break. You get to keep the pieces, as you've been warned. Also this: > > I also suggest you use the latest qemu for this.
