All of lore.kernel.org
 help / color / mirror / Atom feed
From: Chris Friesen <chris.friesen@genband.com>
To: NeilBrown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Subject: Re: RFC: use TRIM data from filesystems to speed up array rebuild?
Date: Tue, 04 Sep 2012 14:28:59 -0600	[thread overview]
Message-ID: <5046648B.8010905@genband.com> (raw)
In-Reply-To: <20120905062113.05e4f0f4@notabene.brown>

On 09/04/2012 02:21 PM, NeilBrown wrote:
> On Tue, 04 Sep 2012 12:06:26 -0600 Chris Friesen<chris.friesen@genband.com>
> wrote:
>> Hi,
>>
>> I'm not really a filesystem guy so this may be a really dumb question.
>>
>> We currently have an issue where we have a ~1TB RAID1 array that is
>> mostly given over to LVM.  If we swap one of the disks it will rebuild
>> everything, even though we may only be using a small fraction of the space.
>>
>> This got me thinking.  Has anyone given thought to using the TRIM
>> information from filesystems to allow the RAID code to maintain a
>> bitmask of used disk blocks and only sync the ones that are actually used?
>>
>> Presumably this bitmask would itself need to be stored on the disk.
> Something like this?
>    http://neil.brown.name/blog/20110216044002#5

Something like that would indeed cover the use-case that triggered this.

Chris

      reply	other threads:[~2012-09-04 20:28 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-04 18:06 RFC: use TRIM data from filesystems to speed up array rebuild? Chris Friesen
2012-09-04 19:11 ` Ric Wheeler
2012-09-04 20:24   ` NeilBrown
2012-09-04 22:59     ` Ric Wheeler
2012-09-06 17:17     ` Benjamin ESTRABAUD
2012-09-06 18:42       ` David Brown
2012-09-07  9:23         ` Benjamin ESTRABAUD
2012-09-04 20:21 ` NeilBrown
2012-09-04 20:28   ` Chris Friesen [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=5046648B.8010905@genband.com \
    --to=chris.friesen@genband.com \
    --cc=linux-raid@vger.kernel.org \
    --cc=neilb@suse.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.