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Date: Fri, 18 Oct 2013 12:38:04 +0200
From: Lars Ellenberg <lars.ellenberg@linbit.com>
To: drbd-dev@lists.linbit.com
Message-ID: <20131018103804.GT17724@soda.linbit>
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Subject: Re: [Drbd-dev] DRBD Trim/discard
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On Thu, Oct 17, 2013 at 04:00:54PM -0700, Eric Wheeler wrote:
> 
> On Fri, 27 Sep 2013, Lars Ellenberg wrote:
> >On Thu, Sep 26, 2013 at 12:01:40PM -0700, Eric Wheeler wrote:
> >>We would like to run DRBD backed by thin-provisioned volumes (think
> >>ZFS or dm-thinp) which require discard support to dereference unused
> >>block allocations.
> >
> >We are integrating DISCARD / TRIM support into our currently
> >pending DRBD 8.4.4 release, right now. Code changes expected to be
> >pushed with the RC2, latest early next week.
> >
> >Thanks for testing and feedback,
> 
> I just sat down to look into TRIM support in the git tree, none of
> the commits in the shortlog are obvious. Has this already been
> committed? If so, do you have a commit number or alternate git tree
> that I can pull down?

You've been grepping for TRIM, I guess, where we used DISCARD ;-)

Look for "DISCARD" in the commit subjects.
I think it starts with
    drbd: prepare receiving side for REQ_DISCARD

Then a few more, and a few fixes for when exactly to expose QUEUE_FLAG_DISCARD.

Cheers,
	Lars