Hey all, I''ve been lurking about for a few days now, and I''m already confused :) At the moment we''ve got a dual quad-core Intel server running Xen 3.3.0 and 4 XP SP3 domUs, and the performance is horrible. Less than a fifth of the performance of an XP install straight on a dual-core opteron. The performance is probably due to the use of GPLPV 0.9.10 (shutdownmon didn''t work with 11), each domU having 2 VCPUs, and the use of tap:aio: over LVM to get round a weird linux software raid10/LVM/HVM guest issue. It''s also unreliable, but that''s a hardware issue. So, we want to build another machine, and go with Windows 2003 R2 Server (standard, SP3, I believe), it also won''t use software raid10 so we can go back to phy: (the work load does very little disk IO anyway). The hardware will be exactly the same. Could anyone advise me on the best means to install 2k3 R2, with 2 CPUs per domU, and GPLPV, please? Thanks -- Mike Williams _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Mike, I currently use Xen 3.2.0 from SLES 10 SP2. I have several of these machines, backed by an FC SAN. My domUs all use file:-based access (loop devices, essentially) to access their disks. One of those systems (Dell PE1950, 2 x Quad-Core Xeon 2.66 Ghz, 16GB of RAM) runs 20-25 Windows XP SP3-based domUs with no performance issues at all. At initial boot, sometimes there''s a good deal of CPU usage on dom0, but that only lasts for a little while, then things settle down. My domUs are (mostly) single vCPU with 384MB of RAM assigned to each domU. I have one that has 1GB of RAM and one that has two vCPUs. On another machine (identical hardware), I also have a Windows Server 2003 domU running, with 2.5GB of RAM assigned and 2 vCPUs. All of the XP domUs and the Server 2k3 domU use the GPL PV drivers. I''ll have to figure out which version - I don''t remember the exact release off the top of my head. I''m not sure what the performance of tap:aio is supposed to be, but loop (file) works fine for me. I can imagine that the software RAID would have a negative impact on performance. Since I''m using SAN-backed volumes for storing my domU files, I''m not running any software RAID inside the domUs or on the dom0s, so that''s not an issue for me. Hope that helps... -Nick>>> Mike Williams <mike@gaima.co.uk> 2009/01/06 13:47 >>>Hey all, I''ve been lurking about for a few days now, and I''m already confused :) At the moment we''ve got a dual quad-core Intel server running Xen 3.3.0 and 4 XP SP3 domUs, and the performance is horrible. Less than a fifth of the performance of an XP install straight on a dual-core opteron. The performance is probably due to the use of GPLPV 0.9.10 (shutdownmon didn''t work with 11), each domU having 2 VCPUs, and the use of tap:aio: over LVM to get round a weird linux software raid10/LVM/HVM guest issue. It''s also unreliable, but that''s a hardware issue. So, we want to build another machine, and go with Windows 2003 R2 Server (standard, SP3, I believe), it also won''t use software raid10 so we can go back to phy: (the work load does very little disk IO anyway). The hardware will be exactly the same. Could anyone advise me on the best means to install 2k3 R2, with 2 CPUs per domU, and GPLPV, please? Thanks -- Mike Williams This e-mail may contain confidential and privileged material for the sole use of the intended recipient. If this email is not intended for you, or you are not responsible for the delivery of this message to the intended recipient, please note that this message may contain SEAKR Engineering (SEAKR) Privileged/Proprietary Information. In such a case, you are strictly prohibited from downloading, photocopying, distributing or otherwise using this message, its contents or attachments in any way. If you have received this message in error, please notify us immediately by replying to this e-mail and delete the message from your mailbox. Information contained in this message that does not relate to the business of SEAKR is neither endorsed by nor attributable to SEAKR. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> > Mike, > I currently use Xen 3.2.0 from SLES 10 SP2. I have several of these > machines, backed by an FC SAN. My domUs all use file:-based access(loop> devices, essentially) to access their disks. One of those systems(Dell> PE1950, 2 x Quad-Core Xeon 2.66 Ghz, 16GB of RAM) runs 20-25 WindowsXP> SP3-based domUs with no performance issues at all. At initial boot, > sometimes there''s a good deal of CPU usage on dom0, but that onlylasts> for a little while, then things settle down. My domUs are (mostly)single> vCPU with 384MB of RAM assigned to each domU. I have one that has 1GBof> RAM and one that has two vCPUs. > > On another machine (identical hardware), I also have a Windows Server2003> domU running, with 2.5GB of RAM assigned and 2 vCPUs. All of the XPdomUs> and the Server 2k3 domU use the GPL PV drivers. I''ll have to figureout> which version - I don''t remember the exact release off the top of myhead.> > I''m not sure what the performance of tap:aio is supposed to be, butloop> (file) works fine for me. I can imagine that the software RAID wouldhave> a negative impact on performance. Since I''m using SAN-backed volumesfor> storing my domU files, I''m not running any software RAID inside thedomUs> or on the dom0s, so that''s not an issue for me. >I''ve just migrated from a low end HP raid controller (E200) running RAID1 to software RAID1. My benchmark was doing backup exec restores from a physical machine onto a DomU (connected via gigabit Ethernet). Some approximate data points were: E200+file:+GPLPV = 320MB/min but the Dom0 would freeze after about 8GB restored and the restore would fail E200+tap:aio+GPLPV = 12MB/min. This would probably run to completion but I wasn''t going to wait E200+file:+qemu = 270MB/min and restored to completion SW RAID+tap:aio+GPLPV = 620MB/min (and everything remains responsive the entire time) Obviously something was wrong somewhere for the E200 to perform that badly, but don''t underestimate the performance of software raid, especially RAID1 (I wouldn''t recommend RAID[56] to anyone who cares about performance, be it hardware or software RAID). James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Tuesday 06 January 2009 22:58:18 James Harper wrote:> E200+file:+GPLPV = 320MB/min but the Dom0 would freeze after about 8GB > restored and the restore would fail > > E200+tap:aio+GPLPV = 12MB/min. This would probably run to completion but > I wasn''t going to wait > > E200+file:+qemu = 270MB/min and restored to completion > > SW RAID+tap:aio+GPLPV = 620MB/min (and everything remains responsive the > entire time)Very interesting numbers there James. I''m a RAID10 man myself, but there is some chunk alignment issue with Xen, HVM guests (possible just windows, I didn''t try), and LVM, or something.> Obviously something was wrong somewhere for the E200 to perform that > badly, but don''t underestimate the performance of software raid, > especially RAID1 (I wouldn''t recommend RAID[56] to anyone who cares > about performance, be it hardware or software RAID).Heh, I''ve just built this new machine with RAID6 :) Your 620MB/min test, was that tap:aio on a file, or lvm, or ...? Might go back to RAID10 and skip the LVs instead, I won''t ever resize these images. Nick, James, would you mind sharing your xen configs for 2 vpcu win2k3 domUs please? Thanks -- Mike Williams _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Here you go... name="2k3Guest" memory=2048 vcpus=2 on_poweroff="destroy" on_reboot="restart" on_crash="destroy" localtime=1 builder="hvm" extid=0 device_model="/usr/lib/xen/bin/qemu-dm" kernel="/usr/lib/xen/boot/hvmloader" boot="c" disk=[ ''file:/var/lib/xen/2k3Guest/disk0,hda,w'', ''file:/var/lib/xen/iso/2k3.iso,hdc:cdrom,r'', ] vif=[ ''mac=00:16:3e:55:ff:13,bridge=xenbr1'',''mac=00:16:3e:76:32:af,bridge=xenbr2'' ] stdvga=0 vnc=1 vncunused=1 apic=1 acpi=1 pae=1 usb=1 usbdevice=''tablet'' serial="pty" -Nick>>> Mike Williams <mike@gaima.co.uk> 2009/01/07 07:04 >>>On Tuesday 06 January 2009 22:58:18 James Harper wrote:> E200+file:+GPLPV = 320MB/min but the Dom0 would freeze after about 8GB > restored and the restore would fail > > E200+tap:aio+GPLPV = 12MB/min. This would probably run to completion but > I wasn''t going to wait > > E200+file:+qemu = 270MB/min and restored to completion > > SW RAID+tap:aio+GPLPV = 620MB/min (and everything remains responsive the > entire time)Very interesting numbers there James. I''m a RAID10 man myself, but there is some chunk alignment issue with Xen, HVM guests (possible just windows, I didn''t try), and LVM, or something.> Obviously something was wrong somewhere for the E200 to perform that > badly, but don''t underestimate the performance of software raid, > especially RAID1 (I wouldn''t recommend RAID[56] to anyone who cares > about performance, be it hardware or software RAID).Heh, I''ve just built this new machine with RAID6 :) Your 620MB/min test, was that tap:aio on a file, or lvm, or ...? Might go back to RAID10 and skip the LVs instead, I won''t ever resize these images. Nick, James, would you mind sharing your xen configs for 2 vpcu win2k3 domUs please? Thanks -- Mike Williams This e-mail may contain confidential and privileged material for the sole use of the intended recipient. If this email is not intended for you, or you are not responsible for the delivery of this message to the intended recipient, please note that this message may contain SEAKR Engineering (SEAKR) Privileged/Proprietary Information. In such a case, you are strictly prohibited from downloading, photocopying, distributing or otherwise using this message, its contents or attachments in any way. If you have received this message in error, please notify us immediately by replying to this e-mail and delete the message from your mailbox. Information contained in this message that does not relate to the business of SEAKR is neither endorsed by nor attributable to SEAKR. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> > On Tuesday 06 January 2009 22:58:18 James Harper wrote: > > E200+file:+GPLPV = 320MB/min but the Dom0 would freeze after about8GB> > restored and the restore would fail > > > > E200+tap:aio+GPLPV = 12MB/min. This would probably run to completionbut> > I wasn''t going to wait > > > > E200+file:+qemu = 270MB/min and restored to completion > > > > SW RAID+tap:aio+GPLPV = 620MB/min (and everything remains responsivethe> > entire time) > > Very interesting numbers there James. > I''m a RAID10 man myself, but there is some chunk alignment issue withXen,> HVM guests (possible just windows, I didn''t try), and LVM, orsomething.> > > Obviously something was wrong somewhere for the E200 to perform that > > badly, but don''t underestimate the performance of software raid, > > especially RAID1 (I wouldn''t recommend RAID[56] to anyone who cares > > about performance, be it hardware or software RAID). > > Heh, I''ve just built this new machine with RAID6 :) > Your 620MB/min test, was that tap:aio on a file, or lvm, or ...? Mightgo> back to RAID10 and skip the LVs instead, I won''t ever resize theseimages. tap:aio + lvm + RAID1 James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users