Greetings. I''m running Xen 3.3.1 on Debian Lenny with the packaged 2.6.26 dom0 kernel on amd64. Based on some reading [1], I''ve been lead to believe HVM device model domains can be a performance win, so I did some testing on my setup (Intel E8400, 8 GB, single Seagate ES.2 drive, idle dom0 and WinXP domU). After following the stubdom README, I saw a big performance drop-off immediately, so maybe my configuration needs work. A quick sequential read/write test with ATTO is below, as well as configuration files. The XP instances in question are all clean installs with indexing turned off and otherwise idle (no significant CPU or disk utilization). Prior to jumping into stub domains, this setup has been 100% stable. Native: http://www.zxvf.us/images/atto-native.jpg HVM + tap:aio: http://www.zxvf.us/images/atto-hvm-tapaio.jpg HVM + file:/: http://www.zxvf.us/images/atto-hvm-file.jpg HVM + tap:aio + stubdom: http://www.zxvf.us/images/atto-hvm-tapaio-stubdom.jpg HVM + file:/ + stubdom: repeatable blue screen on boot (Partmgr.sys) ----- # cat winxptest kernel = "/usr/lib/xen/boot/hvmloader" builder = "hvm" name = "winxptest" memory = "512" disk = [ ''tap:aio:/home/xen/winxptest.img,ioemu:hda,w'', ] vif = [ ''type=ioemu,bridge=eth0'', ] vfb = [''type=vnc,vncunused=1''] localtime = 1 boot = "c" on_reboot = ''restart'' on_crash = ''destroy'' ----- # cat winxpstub kernel = "/usr/lib/xen/boot/hvmloader" builder = "hvm" device_model = "/usr/lib/xen/bin/stubdom-dm" name = "winxpstub" memory = "512" vif = [ ''type=ioemu,bridge=eth0'', ] localtime = 1 boot = "c" on_reboot = ''restart'' on_crash = ''destroy'' ----- # cat winxpstub-dm kernel = "/usr/lib/xen/boot/ioemu-stubdom.gz" disk = [ ''tap:aio:/home/xen/winxptest.img,hda,w'', ] vif = [ '''', ''bridge=eth0'', ] vfb = [''type=vnc,vncunused=1''] ----- Thanks for any tips. Brian Conway _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Fajar A. Nugraha
2009-Apr-10 04:13 UTC
Re: [Xen-users] Poor disk I/O with HVM stub domains
On Fri, Apr 10, 2009 at 10:30 AM, Brian Conway <xen@zxvf.us> wrote:> idle dom0 and WinXP domU). After following the stubdom README, I saw a > big performance drop-off immediately,> Thanks for any tips.A user has reported good results with xen.org''s version (not Lenny''s package), so you might want to try that first (just in case the problem is Lenny''s packages) http://lists.xensource.com/archives/html/xen-users/2009-01/msg00590.html Personally, if your goal is to improve IO performance for XP domUs, I''d suggest using GPLPV drivers instead of stubdom. Annoucement for the latest version is here http://www.nabble.com/New-version-of-GPL-PV-drivers-for-Windows-0.10.0.47-td22867090.html Older version (which have received more testing) is also available at http://meadowcourt.org/downloads/ (I''m using 0.9.12-pre13), so if you have problems with the latest version you can use this one. Regards, Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Fri, 10 Apr 2009 11:13:57 +0700 "Fajar A. Nugraha" <fajar@fajar.net> wrote:> On Fri, Apr 10, 2009 at 10:30 AM, Brian Conway <xen@zxvf.us> wrote: > > idle dom0 and WinXP domU). After following the stubdom README, I saw > > a big performance drop-off immediately, > > > Thanks for any tips. > > A user has reported good results with xen.org''s version (not Lenny''s > package), so you might want to try that first (just in case the > problem is Lenny''s packages) > > http://lists.xensource.com/archives/html/xen-users/2009-01/msg00590.html > > Personally, if your goal is to improve IO performance for XP domUs, > I''d suggest using GPLPV drivers instead of stubdom. Annoucement for > the latest version is here > > http://www.nabble.com/New-version-of-GPL-PV-drivers-for-Windows-0.10.0.47-td22867090.html > > Older version (which have received more testing) is also available at > http://meadowcourt.org/downloads/ (I''m using 0.9.12-pre13), so if you > have problems with the latest version you can use this one. >Thank you. I''m familiar with the GPL PV drivers and am testing them separately. My goal is to understand the functionality and performance of HVM stub domains ( http://blog.xen.org/index.php/2008/08/28/xen-33-feature-hvm-device-model-domain/ ). I see the same drop-off in performance in both Windows and FreeBSD HVMs, which I wouldn''t expect based on the above link, and GPL PV isn''t an option in the latter case (although testing 8-CURRENT as a PV guest is). The kernel version could be the issue, it appears I''m not the only one with this problem ( http://lists.xensource.com/archives/html/xen-devel/2009-04/msg00369.html ). I''m not familiar with all the nuances of the Xen.org 2.6.18 kernel, does it include backported drivers, or is it strictly 2.6.18 + Xen? The ICH9 chipset on my motherboard wasn''t supported in Debian until the Etch-And-A-Half release with 2.6.24. Brian _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users