Il 20/03/2013 11:37, George Dunlap ha scritto: >> That is true. My guess is that nobody really migrates HVM guests without >> PV drivers installed (it's not even possible on XenServer but xl let you >> do that if you want to). When the PV drivers initialize at boot time, >> the IDE disk is closed. Therefore we wouldn't have this problem. >> >> Maybe we should prevent HVM guest migration without PV drivers with xl >> too. Ian, what do you think? > > We should be able to make it safe if we just make sure that qemu does a > metadata sync / FS sync when we ask qemu to write the save file.
To make it safe, just use cache=none. There are downsides (for example tmpfs does not support it), but perhaps you can use a global option or environment variable to toggle the behavior. Is xl still using the driver:subdriver:/path,readonly syntax? That's really inflexible compared to libvirt's XML... Paolo
