From: Eric Sandeen <sandeen@sandeen.net>
To: Bernhard Gschaider <bgschaid_lists@ice-sf.at>
Cc: xfs@oss.sgi.com
Subject: Re: XFS-filesystem corrupted by defragmentation
Date: Tue, 13 Apr 2010 11:36:36 -0500 [thread overview]
Message-ID: <4BC49D94.8090402@sandeen.net> (raw)
In-Reply-To: <87r5mjpn8l.fsf@workstation006.office.ice-sf.at>
On 04/13/2010 07:10 AM, Bernhard Gschaider wrote:
>
> Hi!
>
> I'm asking here because I've been referred here fro the CentOS-mailing
> list (for the full story see
> http://www.pubbs.net/201004/centos/17112-centos-performance-problems-with-xfs-on-centos-54.html
> and
> http://www.pubbs.net/201004/centos/24542-centos-xfs-filesystem-corrupted-by-defragmentation-was-performance-problems-with-xfs-on-centos-54.html
> the following stuff is a summary of this)
>
> It was suggested to me that the source of my performance problems might
> be the fragmentation of the XFS-system. I tested for fragmentation and
> got
>
> xfs_db> frag
> actual 6349355, ideal 4865683, fragmentation factor 23.37%
so on average your filesystem has 6349355/4865683 = 1.3 extents per file.
Just as a casual side note, this is not even remotely bad, at least
on average.
> Before I'd try to defragment my whole filesystem I figured "Let's try
> it on some file".
>
> So I did
>
>> xfs_bmap /raid/Temp/someDiskimage.iso
> [output shows 101 extents and 1 hole]
>
> Then I defragmented the file
>> xfs_fsr /raid/Temp/someDiskimage.iso
> extents before:101 after:3 DONE
>
>> xfs_bmap /raid/Temp/someDiskimage.iso
> [output shows 3 extents and 1 hole]
>
> and now comes the bummer: i wanted to check the fragmentation of the
> whole filesystem (just for checking):
>
>> xfs_db -r /dev/mapper/VolGroup00-LogVol04
> xfs_db: unexpected XFS SB magic number 0x00000000
> xfs_db: read failed: Invalid argument
> xfs_db: data size check failed
> cache_node_purge: refcount was 1, not zero (node=0x2a25c20)
> xfs_db: cannot read root inode (22)
So here you did:
# xfs_db -r /dev/mapper/VolGroup00-LogVol04
but below you show:
% xfs_info /raid
> meta-data=/dev/VolGroup00/LogVol05
.... wrong device maybe?
-Eric
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next prev parent reply other threads:[~2010-04-13 16:53 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-13 12:10 XFS-filesystem corrupted by defragmentation Bernhard Gschaider
2010-04-13 14:58 ` Robert Brockway
2010-04-13 15:24 ` Bernhard Gschaider
2010-04-13 16:36 ` Eric Sandeen [this message]
-- strict thread matches above, loose matches on Subject: below --
2010-04-13 16:08 Sebastian Brings
2010-04-13 17:41 ` Bernhard Gschaider
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