[linux-lvm] Trim support on stripped volumes ?

[Mike Snitzer]

On Tue, May 24 2011 at  5:51am -0400,
Franck Routier (personnel) <alci at mecadu.org> wrote:

> I found this commit
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=7b76ec11fec40203836b488496d2df082d5b2022
> that suggests it could work, but I'm not sure at all...

Yes, that is the commit that added discard support to the stripe target,
it works.

> Le mardi 24 mai 2011 à 11:20 +0200, Franck Routier (personnel) a écrit :
> > Hi,
> > 
> > I have set-up of server with 4 SSDs (OCZ Vertex 2) stripped using LVM.
> > Logical volume has been created using the -i 4 option (iostat confirms
> > that the 4 disks work in parallel when I write a file).
> > 
> > Ext4 fs is used on the volume, mounted with -discard option.

When using -o discard, ext4 will log a warning if a discard failed (and
will disable discards).

So ext4 is a great indicator for whether discards are working on your
striped LV volume.

Mike