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From: Dave Chinner <david@fromorbit.com>
To: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
Cc: "xfs@oss.sgi.com" <xfs@oss.sgi.com>
Subject: Re: xfs_growfs / planned resize / performance impact
Date: Sun, 5 Aug 2012 08:43:36 +1000	[thread overview]
Message-ID: <20120804224336.GS2877@dastard> (raw)
In-Reply-To: <5017E426.2040709@profihost.ag>

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....

> Should i take care of that and format these disks with special parameters?
> 
> I've discovered that a 500GB volume has agcount=4 and 64000 blocks
> of internal log - while a 300GB volume resized to 500GB has agcount
> 7 ad only 40960 blocks of internal log.

I doubt you'll ever notice the difference.

> 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....

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

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  parent reply	other threads:[~2012-08-04 22:43 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 [this message]
2012-08-05  5:46   ` Stefan Priebe
2012-08-05 11:06     ` Martin Steigerwald
2012-08-05 11:35     ` Andy Bennett
2012-08-05 20:57     ` Dave Chinner

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