Re: xfsrepair memory consumption

[David Chinner <dgc@sgi.com>]

On Tue, Mar 20, 2007 at 03:32:05PM +0100, Daniele P. wrote:
> Hi all,
> I'm just asking if any work has been done/is in progress to improve
> xfs_repair memory consumption.

Work is in progress, but it won't really solve your problem.
See, you've got:

> enceladus:~# df -i /dev/sdb1
> Filesystem            Inodes   IUsed   IFree IUse% Mounted on
> /dev/sdb1            293049664 6511481 286538183    3% /media/300

6 million inodes in your filesystem, and a certain points in
repair we have to hold indexes of them all (plus some state) in
memory. Phase 6 is one of these points.

In terms of inode count, I generally use the rule that for every
10million inodes you need a gigabyte of RAM for repair - you needed
about 500MB for 6million inodes.

We have been trimming bits and pieces off this per-inode usage
but there comes a point where you just need more memory. That
is, as filesystem size grows, so does the amount of memory
needed to repair it in a finite time....

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group