From: Spelic <spelic@shiftmail.org>
To: Eric Sandeen <sandeen@sandeen.net>, Spelic <spelic@shiftmail.org>,
xfs@oss.sgi.com
Subject: Re: XFS shrinking planned?
Date: Wed, 29 Oct 2014 10:37:36 +0100 [thread overview]
Message-ID: <5450B560.6000208@shiftmail.org> (raw)
In-Reply-To: <544FD4C1.4020004@sandeen.net>
On 28/10/2014 18:39, Eric Sandeen wrote:
> Not formally planned, there are bits and pieces out there (i.e. the inode
> mover) which are part of what it might take to achieve a shrinker.
>
> Another option, rather than fs shrinking, is to use the dm-thinp target, which
> would allow you to allocate a large-but-sparse block device, create a very
> large filesystem on that, and add or remove storage as needed.
> (At least I think you can remove it...!)
>
> -Eric
Thanks for your reply Eric
Interesting technique, but for enforcing a maximum size (smaller than
the very large allocated thin device) I would have to rely on quotas,
which probably decreases performance.
Then using thinp would mess up all the disk layout, basically replacing
the XFS allocator, which most likely would decrease performances
significantly.
And then the thinp code itself is a medium performance thing and I don't
think it can keep up with XFS performances, so that would presumably be
a hard bottleneck.
All this would result in a performance almost certainly lower than ext4.
Thanks
S.
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next prev parent reply other threads:[~2014-10-29 9:37 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-28 16:19 XFS shrinking planned? Spelic
2014-10-28 17:39 ` Eric Sandeen
2014-10-29 9:37 ` Spelic [this message]
2014-10-29 13:03 ` Eric Sandeen
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