Hi,
I have some xen domU on Centos 5.2 server.
For some weeks i had a problem with "xen domU" performances.
Indeed my xen domU spend a lot of time in cpu waiting.
Reading some informations on the net it seems to come ith I/O heavy load.
Using collectd in my domU to monitor the "traffic" on virtual disk and
virtuel network i don't see heavy I/O rates.
Thinking my dom0 was overloaded by my domUs i have stopped all my domUs
except one but the problem persist.
I don't know how to get more informations in order to solve my problem.
For information our config is :
- Hitachi SAN infrastructure
- DELL 1950 servers with 2 qlogic hba adapters (we used qla2xx drivers
and linux dm-multipath for multipathing )
- We have 1 LUN on the SAN for each domU
- The dom0 manage theses LUNs using LVM
- A domU xen disk configuration looks like this : disk = [
'phy:/dev/VolGroupIdp/LogVolIdp-disk,xvda1,w']
- In the domU we doesn't use LVM.
- At the network level we share a gigabit interface with all the domU
using linux bridges. Each bridge refer to a different vlan.
Anyone encoutered I/O performances problems with latests centos 5.2 xen
releases ? (In fact i don't really understand if it's a xen problem or a
"hardware" problem)
Regards
--
Frederic Soulier
Administrateur Reseau
Centre de Ressources Informatiques
Universit? Toulouse 1 Sciences Sociales
2 RUE DU DOYEN GABRIEL MARTY
31042 TOULOUSE CEDEX 9
Tel : +33 5 61 63 39 98 / +33 5 61 63 39 98
Fax : +33 5 61 63 37 98 Bureau : AR38 bis
http://cri.univ-tlse1.fr/
