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Subject: Re: [linux-lvm] lvm2: zeroing free space
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To: LVM general discussion and development <linux-lvm@redhat.com>

On Fri, Feb 4, 2011 at 10:54 PM, Mike Snitzer <snitzer@redhat.com> wrote:
> On Fri, Feb 04 2011 at =EF=BF=BD9:12am -0500,
> Bryn M. Reeves <bmr@redhat.com> wrote:
>> They wanted a method to write zeros to all the unallocated space in a VG=
 to
>> trigger a reclaim of unused regions in the VG's PVs.

Probably not directly relevant, but perhaps of interest to those who
haven't come across it before.

Zerofree is designed to do this for loopback filesystems; I came
across it in the context of union/aufs overlays, via Grml's changelog

http://intgat.tigress.co.uk/rmy/uml/sparsify.html