samba - Dec 2010 - Samba slowness serving SAN-based GFS2 filesystems

Ok,

I'm experiencing slowness serving SAN-based GFS2 filesystems (of a specific
SAN configuration).
Here's my layout:

I have a server cluster.
OS= RHEL 5.4 (both nodes...)
kernel= 2.6.18-194.11.3.el5
Samba= samba-3.0.33-3.14.el5

*On this cluster are 6 GFS2 Clustered filesystems.
*4 of these volumes belong to one huge LUN (1.8 TB), spanning 8 disks.  The
other 2 remaining volumes are 1 to 1 with their own LUN's, respectively.
*The 2 volumes which are 1 to 1 with their LUN's are serving out the volume
with a very acceptable throughput.
*Unfortunately, the 4 volumes which reside within the monster 1.8 TB LUN get
served out at approx half the throughput speed as that of the 2 solitary
LUN's.
*EMC recommends SAN volumes be configured this way (1 LUN over many disks,
housing multiple LVM's and FS's if need be.


*For testing purposes, I requested new SAN volumes to work.
*These new volumes are 1 to 1 with their LUN's, spanning 8 disks.  (4
LVM's
on 4 LUN's spanning 8 disks).
*After putting a GFS2 filesystem on the new volumes, I shared them out.
*My throughput of a 3 GB ISO to 2 of the test volumes is twice as fast as
the throughput on the Filesystems that live on the monster LUN.

***IS THERE SOME SORT OF SAMBA *LIMITATION *REGARDING *MANY LVM's w/ GFS2
FILESYSTEMS ON 1 BIG LUN SPANNING MANY DISKS*?

Any Ideas?

Thanks,

-- 
Brett B. Klingensmith
Sr. Systems Administrator
ANSYS, Inc.
Southpointe
275 Technology Drive
Canonsburg, PA 15317
Phone: 724.514.2970
Fax:     724.514.3117
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On Tue, Dec 14, 2010 at 05:55:51PM -0500, Brett Klingensmith
wrote:
> ***IS THERE SOME SORT OF SAMBA *LIMITATION *REGARDING *MANY LVM's w/
GFS2
> FILESYSTEMS ON 1 BIG LUN SPANNING MANY DISKS*?
No. Performance analysis sometimes is difficult, but as it
seems that the file system and lvm layout is the only thing
you changed, I would recommend contacting RedHat for
performance hints.

Volker