Re: [Qemu-devel] [PATCH 2/2] qemu-ga: add guest-fstrim command

[Chris Wedgwood]

> FITRIM is a mounted filesystem feature to discard (or "trim") blocks which
> are not in use by the filesystem. This is useful for solid-state drives
> (SSDs) and thinly-provisioned storage.  Provide access to the feature
> from the host so that filesystems can be trimmed periodically or before
> migration.

Why can't we use the block layer for this?   AHCI (I think) already
has support, others could be added some some coordination.

That was existing operating systems with current filesystems will DTRT
when needed.