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

[Pat Riehecky]

On 04/15/2013 09:02 AM, Daryl Herzmann wrote:
> Thanks for your help.
>
> On Mon, Apr 15, 2013 at 8:39 AM, Pat Riehecky <riehecky at fnal.gov 
> <mailto: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
>

I would agree, your drive looks nice and optimized..... this thread already 
has you checking for lazy counts.... those are my two "tricks" for getting XFS 
to run beautifully.  But I've never had a volume over 8TB before.....

Pat

-- 
Pat Riehecky

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/rhelv6-list/attachments/20130415/8dd9e6f2/attachment.htm>