Gordon Messmer gordon.messmer at gmail.com Wed Jun 24 01:42:13 UTC 2015 > I wondered the same thing, especially in the context of someone who > prefers virtual machines. LV-backed VMs have *dramatically* better disk > performance than file-backed VMs. I did a bunch of testing of Raw, qcow2, and LV backed VM storage circa Fedora 19/20 and found very little difference. What mattered most was the (libvirt) cache setting, accessible by virsh edit the xml config or virt-manager through the GUI. There have been a lot of optimizations in libvirt and qemu that make qcow2 files perform comparable to LVs. For migrating VMs, it's easier if they're a file. And qcow2 snapshots are more practical than LVM (thick) snapshots. The thin snapshots are quite good though they take a lot of familiarity with setting them up. -- Chris Murphy