From: Chris Mason <chris.mason@oracle.com>
To: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: linux-btrfs@vger.kernel.org, lkml@rtr.ca
Subject: Re: fallocate overhead
Date: Thu, 13 Aug 2009 10:45:23 -0400 [thread overview]
Message-ID: <20090813144523.GG4652@think> (raw)
In-Reply-To: <20090813140732.GA1915@phenom2.trippelsdorf.de>
On Thu, Aug 13, 2009 at 04:07:32PM +0200, Markus Trippelsdorf wrote:
> I was playing with the new hdparm wiper script (
> http://sourceforge.net/projects/hdparm/files/) on my Vertex SSD and
> it appears that btrfs needs a huge space overhead when dealing with
> fallocate system calls. Basically what the wiper script does is to
> fallocate one huge file using all free space minus a safety margin.
> And this margin has to be about 30% on btrfs, e.g.:
We're actively fixing this ;) The margin is just a hard coded limit to
try and avoid enospc oopsen. It should improve in 2.6.32.
-chris
prev parent reply other threads:[~2009-08-13 14:45 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-13 14:07 fallocate overhead Markus Trippelsdorf
2009-08-13 14:45 ` Chris Mason [this message]
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