[rhelv6-list] RHEL6.2 XFS brutal performence with lots of files

[Daryl Herzmann]

Thanks for your help.

On Mon, Apr 15, 2013 at 8:39 AM, Pat Riehecky <riehecky at fnal.gov> wrote:

>  I've run into some terrible performance when I've had a lot of
> add/remove actions on the filesystem in parallel.  They were mostly due to
> fragmentation.  Alas, XFS can get some horrid fragmentation.
>
> xfs_db -c frag -r /dev/<node>
>
> should give you the stats on its fragmentation.
>

# xfs_db -c frag -r /dev/md127
actual 140539575, ideal 139998847, fragmentation factor 0.38%

Here's an iostat snapshot while I was running xfs_db, the tps numbers for
md127 seem strange.  sd[b-f] are a part of the raid5....

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           5.12    0.00    7.12    8.81    0.00   78.94

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
sda              35.00      1032.00       656.00       1032        656
sdc             458.00     32451.00       680.00      32451        680
sde             451.00     30936.00       544.00      30936        544
sdb             573.00     32448.00       784.00      32448        784
sdd             527.00     30728.00       696.00      30728        696
sdf             593.00     31736.00       624.00      31736        624
md127         157986.00    157983.00      1592.00     157983       1592



> I can't speak for others, but I've got 'xfs_fsr' linked into
> /etc/cron.weekly/ on my personal systems with large XFS filesystems.
>

Seems like I shouldn't have to do that given the numbers above?

daryl

-- 
> Pat Riehecky
>
> Scientific Linux developerhttp://www.scientificlinux.org/
>
>
> _______________________________________________
> rhelv6-list mailing list
> rhelv6-list at redhat.com
> https://www.redhat.com/mailman/listinfo/rhelv6-list
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/rhelv6-list/attachments/20130415/1202e8b2/attachment.htm>