Stephane ROZET
2011-Feb-18 13:29 UTC
[Xen-users] Xen-4.0 and GPLPV Driver - Slow Write perf
Hi, Im using 3 servers with XEN and 2 San. Twice have Xen3.2 and Windows VM are OK with GPLPV drivers. One server have Xen-4.0 and I have a problem with Windows VM: Windows VM have very poor write disk performance (3 MB/s) with GPLPV driver (I tried 0.9 and 0.11 versions). Read perf are ok (~200MB/s). Without GPLPV driver, its more credible, but Im not using the best of my VM without GPLPV Xen host is Debian 6, with kernel 2.6.32-5. Im using AOE, with AOEtools in version 32 and aoe driver in version 76. What can I do for that ? Thanks Stéphane _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
ROZET Stéphane
2011-Feb-18 13:34 UTC
[Xen-users] Xen-4.0 and GPLPV Driver - Slow Write perf
Hi, I''m using 3 servers with XEN and 2 San. Twice have Xen3.2 and Windows VM are OK with GPLPV drivers. One server have Xen-4.0 and I have a problem with Windows VM: Windows VM have very poor write disk performance (3 MB/s) with GPLPV driver (I tried 0.9 and 0.11 versions). Read perf are ok (~200MB/s). Without GPLPV driver, it''s more credible, but I''m not using the best of my VM without GPLPV... Xen host is Debian 6, with kernel 2.6.32-5. I''m using AOE, with AOEtools in version 32 and aoe driver in version 76. What can I do for that ? Thanks Stéphane Stéphane ROZET Ingénieur réseaux et systèmes 2, rue Maurice Hartmann 92130 Issy-les-Moulineaux Fixe : 01.55.95.94.29 Fax : 01.46.44.29.80 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Stephane ROZET
2011-Feb-18 13:35 UTC
[Xen-users] Xen-4.0 and GPLPV Driver - Slow Write perf
Hi, Im using 3 servers with XEN and 2 San. Twice have Xen3.2 and Windows VM are OK with GPLPV drivers. One server have Xen-4.0 and I have a problem with Windows VM: Windows VM have very poor write disk performance (3 MB/s) with GPLPV driver (I tried 0.9 and 0.11 versions). Read perf are ok (~200MB/s). Without GPLPV driver, its more credible, but Im not using the best of my VM without GPLPV Xen host is Debian 6, with kernel 2.6.32-5. Im using AOE, with AOEtools in version 32 and aoe driver in version 76. What can I do for that ? Thanks Stéphane _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
James Harper
2011-Feb-18 13:44 UTC
RE: [Xen-users] Xen-4.0 and GPLPV Driver - Slow Write perf
> > Hi, > > I''m using 3 servers with XEN and 2 San. Twice have Xen3.2 and WindowsVM are> OK with GPLPV drivers. One server have Xen-4.0 and I have a problemwith> Windows VM: > > Windows VM have very poor write disk performance (3 MB/s) with GPLPVdriver (I> tried 0.9 and 0.11 versions). Read perf are ok (~200MB/s). > > Without GPLPV driver, it''s more credible, but I''m not using the bestof my VM> without GPLPV... > > Xen host is Debian 6, with kernel 2.6.32-5. I''m using AOE, withAOEtools in> version 32 and aoe driver in version 76. > > What can I do for that ? >How are you testing performance? If the performance testing tool issues overlapping writes or unaligned writes then performance will suffer badly. If you are using the _debug version of the drivers then the logging done for overlapped writes might kill performance too. If you are using the _debug version of GPLPV, please send me a copy of your /var/log/xen/qemu-dm-<domU name>.log file after doing performance tests. Do you have a local disk you can test with to rule out any strange interaction with AoE? What is cpu load in Dom0 and DomU when writing? Can you test a Linux DomU and make sure the problem is definitely related to GPLPV? Also what is network performance like for your Windows DomU? Thanks James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Stephane ROZET
2011-Feb-18 14:13 UTC
RE: [Xen-users] Xen-4.0 and GPLPV Driver - Slow Write perf
Hi James, I''m using crystaldiskmark and a simple copy/paste to test performance and there is big difference between GPLPV driver and without. I run a linux, and test with hdparm for read perf and dd for write perf. It seems to be ok: Read and Write never goes under 30 MB/s. (always > 30 MB/s) For the network perf, I didn''t see anything particular. I didn''t use _debug gplpv driver, should i? Stéphane -----Message d''origine----- De : xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] De la part de James Harper Envoyé : vendredi 18 février 2011 14:44 À : Stephane ROZET; xen-users@lists.xensource.com Objet : RE: [Xen-users] Xen-4.0 and GPLPV Driver - Slow Write perf> > Hi, > > I''m using 3 servers with XEN and 2 San. Twice have Xen3.2 and WindowsVM are> OK with GPLPV drivers. One server have Xen-4.0 and I have a problemwith> Windows VM: > > Windows VM have very poor write disk performance (3 MB/s) with GPLPVdriver (I> tried 0.9 and 0.11 versions). Read perf are ok (~200MB/s). > > Without GPLPV driver, it''s more credible, but I''m not using the bestof my VM> without GPLPV... > > Xen host is Debian 6, with kernel 2.6.32-5. I''m using AOE, withAOEtools in> version 32 and aoe driver in version 76. > > What can I do for that ? >How are you testing performance? If the performance testing tool issues overlapping writes or unaligned writes then performance will suffer badly. If you are using the _debug version of the drivers then the logging done for overlapped writes might kill performance too. If you are using the _debug version of GPLPV, please send me a copy of your /var/log/xen/qemu-dm-<domU name>.log file after doing performance tests. Do you have a local disk you can test with to rule out any strange interaction with AoE? What is cpu load in Dom0 and DomU when writing? Can you test a Linux DomU and make sure the problem is definitely related to GPLPV? Also what is network performance like for your Windows DomU? Thanks James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users