From: Martin Steigerwald <Martin@lichtvoll.de>
To: xfs@oss.sgi.com
Cc: Stefan Priebe <s.priebe@profihost.ag>
Subject: Re: xfs_growfs / planned resize / performance impact
Date: Sun, 5 Aug 2012 13:06:56 +0200 [thread overview]
Message-ID: <201208051306.56937.Martin@lichtvoll.de> (raw)
In-Reply-To: <C4E0639A-87DE-4D38-8097-9B71D0947ABE@profihost.ag>
Am Sonntag, 5. August 2012 schrieb Stefan Priebe:
> Am 05.08.2012 um 00:43 schrieb Dave Chinner <david@fromorbit.com>:
> > On Tue, Jul 31, 2012 at 03:56:54PM +0200, Stefan Priebe - Profihost AG
wrote:
> >> Hello list,
> >>
> >> i'm planning to create a couple of VMs with just 30GB of space while
> >> using xfs as the main filesystem.
> >>
> >> Now i alreay know that some of the VMs will grow up to 250GB while
> >> resizing the block device and using xfs_growfs.
> >
> > Just use thin provisioning and make it 250GB to begin with. Thin
> > provisioning mades filsystem grow/shrink pretty much redundant....
>
> But dm thin isn't stable isn't it? Does xfs reallocate used parts of
> the block Device before using new parts? Otherwise deleting and
> recreating files will result in full used space pretty fast.
A periodic fstrim might help if the TRIM/DISCARD is supported in all
layers. And whether it is is a good question that depends on well where
your data is stored and what layers in the kernel are involved in storing
it and the kernel version of course.
> >> Is it a problem if this grow will happen in small portions (30GB =>
> >> 50GB => 75GB => 100GB => ... 300GB)?
> >
> > Growing a filesystem by an order of magnitude is the limit of what
> > I'd suggest is sane. Growing it by two orders of magnitude
> > (espcially if you start with a 16 AG filesystem because of stripe
> > alignment) is going to cause problems with the number of AGs and
> > the subsequent freespace management scale issue....
>
> I would start with ag=4 and end up in ag 48 in my tests.
Thats IMHO quite much for upto 500 GiB. But it still depends on what kind
of storage this is located.
--
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7
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next prev parent reply other threads:[~2012-08-05 11:06 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-31 13:56 xfs_growfs / planned resize / performance impact Stefan Priebe - Profihost AG
2012-07-31 17:27 ` Stan Hoeppner
2012-08-03 4:03 ` Eric Sandeen
2012-08-03 6:09 ` Stefan Priebe - Profihost AG
2012-08-03 13:46 ` Eric Sandeen
2012-08-05 11:03 ` Martin Steigerwald
2012-08-05 12:34 ` Stan Hoeppner
2012-08-05 13:49 ` Martin Steigerwald
2012-08-05 20:26 ` Stan Hoeppner
2012-08-05 15:54 ` Stefan Priebe
2012-08-06 11:42 ` Michael Monnerie
2012-08-04 22:43 ` Dave Chinner
2012-08-05 5:46 ` Stefan Priebe
2012-08-05 11:06 ` Martin Steigerwald [this message]
2012-08-05 11:35 ` Andy Bennett
2012-08-05 20:57 ` Dave Chinner
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