From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Tue, 24 May 2011 09:14:52 -0400
From: Mike Snitzer <snitzer@redhat.com>
Message-ID: <20110524131451.GB27519@redhat.com>
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Subject: Re: [linux-lvm] Trim support on stripped volumes ?
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To: Franck Routier <alci@mecadu.org>
Cc: LVM general discussion and development <linux-lvm@redhat.com>

On Tue, May 24 2011 at  5:51am -0400,
Franck Routier (personnel) <alci@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 � 11:20 +0200, Franck Routier (personnel) a �crit :
> > 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