From mboxrd@z Thu Jan  1 00:00:00 1970
From: NeilBrown <neilb@suse.de>
Subject: Re: RFC: use TRIM data from filesystems to speed up array rebuild?
Date: Wed, 5 Sep 2012 06:21:13 +1000
Message-ID: <20120905062113.05e4f0f4@notabene.brown>
References: <50464322.3010509@genband.com>
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To: Chris Friesen <chris.friesen@genband.com>
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On Tue, 04 Sep 2012 12:06:26 -0600 Chris Friesen <chris.friesen@genband.com>
wrote:

>=20
> Hi,
>=20
> I'm not really a filesystem guy so this may be a really dumb question.
>=20
> We currently have an issue where we have a ~1TB RAID1 array that is=20
> mostly given over to LVM.  If we swap one of the disks it will rebuild=20
> everything, even though we may only be using a small fraction of the spac=
e.
>=20
> This got me thinking.  Has anyone given thought to using the TRIM=20
> information from filesystems to allow the RAID code to maintain a=20
> bitmask of used disk blocks and only sync the ones that are actually used?
>=20
> Presumably this bitmask would itself need to be stored on the disk.
>=20
> Thanks,
> Chris
>=20
>=20

Something like this?
  http://neil.brown.name/blog/20110216044002#5

NeilBrown

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