Re: [libvirt] [libvirt PATCH] qemu: Support discard for disk

On Wed, May 15, 2013 at 02:56:03PM +0200, Paolo Bonzini wrote: > Il 14/05/2013 14:44, Osier Yang ha scritto: >> QEMU introduced "discard" option for drive since commit a9384aff53, >> >> <...> >> @var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and >> controls whether @dfn{discard} (also known as @dfn{trim} or @dfn{unmap}) >> requests are ignored or passed to the filesystem. Some machine types >> may not support discard requests. >> </...> >> >> This patch exposes the support in libvirt. >> >> QEMU supported "discard" for "-drive" since v1.5.0-rc0: > > I would prefer to use ignore/unmap instead of off/on in libvirt. If we think there's any chance QEMU might gain a 3rd possible value for this setting, then I tend to agree with you that avoiding off/on would be desirable.