[libvirt-users] fstrim support in libvirt/qemu guests

[Andrey Korolyov]

On Mon, Nov 3, 2014 at 4:24 PM, Michal Privoznik <mprivozn at redhat.com> 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.