On 03.11.2014 15:04, Brian Rak wrote: > > On 11/3/2014 8:43 AM, Andrey Korolyov wrote: >> On Mon, Nov 3, 2014 at 4:24 PM, Michal Privoznik <mprivozn@xxxxxxxxxx> >> wrote: >>> On 01.11.2014 05:30, Dennis Jacobfeuerborn wrote: >>>> Hi, >>>> I'm trying to find out how to enable fstrim support for libvirt/qemu >>>> guests. Specifically I'm trying to enable this on a CentOS 7 host (qemu >>>> 1.5). I searched the web but only found very vague information and no >>>> clear documentation on the requirements or how to modify the guest xml >>>> to enable discard/fstrim support. >>>> >>>> Can someone point me in the right direction? >>> >>> One thing that you'll need is the guest agent: >>> >>> http://wiki.libvirt.org/page/Qemu_guest_agent >>> >>> Then you can just use: >>> >>> # virsh domfstrim $dom >>> >>> Michal >> ... and probably discard-aware block driver (although I cannot name >> anything except virtio-blk which is not supporting trim or will not >> support in the near future). Not sure to which part, guest-host >> interaction or driver abilities, the initial question belongs. >> >> > > The virtio-scsi driver supports it, though you take a minor performance > hit for switching. Yes, after a bit of experimentation it seems you need to use virtio-scsi and raw images to make this work. Interesting enough then you can even make use of fstrim in a non-SSD context and shrink the used space of the raw image. Regards, Dennis _______________________________________________ libvirt-users mailing list libvirt-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvirt-users
