> I have identified one use-case where KVM Live Backup causes a significant > decrease in IO read performance. > > Start a KVM Live Backup > Inside the VM immediately run: > dd if=/dev/disk_being_backed_up of=/dev/null bs=1M count=8192 > > Repeated same test but used LVM snapshot and vmtar: > lvcreate -L33000M -s -n test-snapshot /dev/vmdisks/vm-108-disk-2 > /usr/lib/qemu-server/vmtar '/etc/pve/qemu-server/108.conf' > 'qemu-server.conf' '/dev/vmdisks/test-snapshot' 'vm-disk'|lzop -o > /backup1/dump/backup.tar.lzop > > KVM Live Backup: 120 seconds or more > LVM Snapshot backup: 55 seconds > With no backup: 45 seconds
Why does that show a "decrease in IO read performance"? I guess the dd inside the VM is much faster with live backup? _______________________________________________ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
