On 08/11/2011, at 8:51 AM, Peter Lees wrote: > > > On 08/11/2011, at 2:22 AM, Avi Kivity <avi@xxxxxxxxxx> wrote: > >> On 11/07/2011 03:57 PM, Peter Lees wrote: >>> hello all >>> >>> when trying to create a VM using a RAW image on a zfs filesystem, i get an >>> "invalid argument" error. >>> >>> has anyone made this work? is it a known issue and/or is there a workaround? >>> [...] >>> full error was: >>> Unable to complete install '<class 'libvirt.libvirtError'> internal error Process exited while reading console log output: char device redirected to /dev/pts/3 >>> qemu: could not open disk image /space/vm_store/elveros_001.raw: Invalid argument >> >> I'm guessing that qemu tried to open the file with O_DIRECT, and >> zfsonlinux doesn't support O_DIRECT. Please try changing the cache mode >> to writeback. >> >>> any suggestions in getting ZFS as the vm_store, working with decent performance ? >>> >> >> zfsonlinux uses fuse, yes? I'd be surprised if you can get decent >> performance with it. > > http://zfsonlinux.org > > this is a source-release kernel module; it doesn't use fuse, and performance is ok for filesystem operations. no good at all for zvol operations, however. > > thanks for the tip, i will give that a go as a follow-up, setting the cache mode to writeback did fix the problem. performance is many times what i was getting with zvols, even if it's not as good as with ext4fs. i now have a more portable vm datastore, however. thanks p -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
