Date: Wed, 23 Jan 2008 09:53:39 +0100
From: Ralf Gross <Ralf-Lists@ralfgross.de>
To: Barry Naujok <bnaujok@sgi.com>
Cc: xfs@oss.sgi.com
Subject: Re: xfs_rapair memory requirement per TB
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Barry Naujok schrieb:
> >
> >Reading the "Repairing a possibly incomplete xfs_growfs command?" thread
> >this month makes me wonder if there is some type of rough formula or
> >guesstimation cheat sheet to figure out how much memory and swap one
> >would need for an xfs_repair given a file system with many terabytes.
> >
> >
> >Say I have an 8TB LUN that needs an xfs_repair.  What would be the rough
> >memory requirements and swap space?
> >
> 
> General rule of thumb at the moment is 128MB of RAM/TB of filesystem
> plus 4MB/million inodes on that filesystem.

Did this change lately? I found the rule of thumb: 2 GB RAM for 1 TB
of disk storage + some RAM per x inodes.

http://oss.sgi.com/archives/xfs/2005-08/msg00045.html

I'm interested in this too, because we'll get additional 15 TB disk
space soon. Until now I created filesystems of max 7-8 TB on a server
with 16 GB RAM. The 15 TB (mostly 2-5 GB large files) will be used on
a server with only 6 GB RAM (debian etch, xfsprogs 2.8.11-1). We plan
to expand the RAM to 12 GB. What size would be safe for a xfs
filesystem on a server with 12 GB RAM (given mostly large files)?

Ralf