[Xen-users] Poor performance with Fibre-channel in domU and dom0

[Simons IT-Service <info@xxxxxxxxxxxxxxxxxxxx>]

Hello,

I have a server with 4GB of Memory, two Intel QuadCore Xeon CPUs and a LSI 
FibreChannel 4GBit HBA Card connected to a SAN-Box.

When I install this with a normal Linux (CentOS 4.4) with kernel 
2.6.9-42.0.3.ELsmp and the mptfc driver, which is deliverd with this kernel, 
everything works fine.

I can copy a 600 MB file from one directory to an other on the same partition 
in 6 seconds.

When I install on the same server a Xen-kernel (2.6.16.29-xen) with the mptfc 
driver, which is deliverd with this kernel, the I/O performance to the SAN is 
very,very,very slow.

When I copy in a domU a 600 MB file from one directory to an other on the same 
partition it take 90 seconds.

The config file for the disk in my domU is this:

disk = [ 'phy:/dev/OracleVG/OraAdmin10gR2,/dev/sda1,w', 
'phy:/dev/OracleVG/OraDumps10gR2,/dev/sda2,w', 
'phy:/dev/OracleVG/OraProduct10gR2,/dev/sda3,w', 
'phy:/dev/OracleVG/OraSoftware10gR2,/dev/sda4,w', 
'phy:/dev/OraDataVG/pdevkh1,/dev/sdb1,w', 
'phy:/dev/OraDataVG/pskh,/dev/sdb2,w', 'phy:/dev/OraDataVG/temp,/dev/sdb3,w', 
'phy:/dev/sda13,/dev/sdc1,w' ]

The filesystem is ext3.

You can see that we would run Oracle 10g R2 in a Xen DomU.
We work with datafiles greater then 6GB.

Copy from a partiton to an other is ok.

Can anybody help us?

greetz from Krefeld,
Germany

Dietmar Simons

-- 
______________________________________________

Simons IT-Service
Dietmar Simons

Matthiasstr. 18a
41468 Neuss
Germany

Phone: 02131 - 153498
Fax: 02131 - 153499
Mobil: 0172 - 253 0523

email: info@xxxxxxxxxxxxxxxxxxxx
http://www.simons-it-service.de
______________________________________________

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users