Hello, I''m new to Xen and after properly configured a couple of Linux based VMs, I''m giving a try to a Windows XP domU. Installation is going just fine, network performances are pretty good after installing the gplpv driver (1Gb link properly recognized), but opening a session and usage is very slow through RDP. I''ve allocated 2Go of memory and 2 procs to the VM but it''s still very slow. Dom0 configuration is pretty robust : - 2x Xeon 1.6GHz - 6Go memory (will soon be upgraded to 12Go) - Linux Debian stable With running 2 Windows domU (so 2x 2Go allocated to the VMs) and a Linux domU (512Mo and 1 proc.), the available memory on the dom0 decrease to less than 200Mo, what negatively impact the VMs performances I think... While google-ing around, I''ve read that adding dom0_mem=<VALUE> to the kernel entry in grub permit to assign a specific amount of memory to the dom0 host. My questions is do you think if I assign 2Go (dom0_mem=2048M) to dom0 host, this could optimize the global performances of the Windows domU ? Linux based domU are running really fine and won''t be that loaded (no GUI installed on them). Thanks for your feedback. Sylvain. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Did you try disabling checksum offloading? On 27 February 2010 14:18, Sylvain Viollat <sviollat@planetmars.fr> wrote:> Hello, > > I''m new to Xen and after properly configured a couple of Linux based VMs, > I''m giving a try to a Windows XP domU. > > Installation is going just fine, network performances are pretty good after > installing the gplpv driver (1Gb link properly recognized), but opening a > session and usage is very slow through RDP. > > I''ve allocated 2Go of memory and 2 procs to the VM but it''s still very > slow. > > Dom0 configuration is pretty robust : > - 2x Xeon 1.6GHz > - 6Go memory (will soon be upgraded to 12Go) > - Linux Debian stable > > With running 2 Windows domU (so 2x 2Go allocated to the VMs) and a Linux > domU (512Mo and 1 proc.), the available memory on the dom0 decrease to less > than 200Mo, what negatively impact the VMs performances I think... > > While google-ing around, I''ve read that adding dom0_mem=<VALUE> to the > kernel entry in grub permit to assign a specific amount of memory to the > dom0 host. > > My questions is do you think if I assign 2Go (dom0_mem=2048M) to dom0 host, > this could optimize the global performances of the Windows domU ? > > Linux based domU are running really fine and won''t be that loaded (no GUI > installed on them). > > Thanks for your feedback. > > Sylvain. > > _______________________________________________ > 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
On Sat, Feb 27, 2010 at 03:18:29PM +0100, Sylvain Viollat wrote:> Hello, > > I''m new to Xen and after properly configured a couple of Linux based > VMs, I''m giving a try to a Windows XP domU. > > Installation is going just fine, network performances are pretty good > after installing the gplpv driver (1Gb link properly recognized), but > opening a session and usage is very slow through RDP. > > I''ve allocated 2Go of memory and 2 procs to the VM but it''s still very slow. > > Dom0 configuration is pretty robust : > - 2x Xeon 1.6GHz > - 6Go memory (will soon be upgraded to 12Go) > - Linux Debian stable > > With running 2 Windows domU (so 2x 2Go allocated to the VMs) and a Linux > domU (512Mo and 1 proc.), the available memory on the dom0 decrease to > less than 200Mo, what negatively impact the VMs performances I think... >See: http://wiki.xensource.com/xenwiki/XenBestPractices -- Pasi> While google-ing around, I''ve read that adding dom0_mem=<VALUE> to the > kernel entry in grub permit to assign a specific amount of memory to the > dom0 host. > > My questions is do you think if I assign 2Go (dom0_mem=2048M) to dom0 > host, this could optimize the global performances of the Windows domU ? > > Linux based domU are running really fine and won''t be that loaded (no > GUI installed on them). > > Thanks for your feedback. > > Sylvain. > > _______________________________________________ > 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
> > Hello, > > I''m new to Xen and after properly configured a couple of Linux based > VMs, I''m giving a try to a Windows XP domU. > > Installation is going just fine, network performances are pretty good > after installing the gplpv driver (1Gb link properly recognized), but > opening a session and usage is very slow through RDP.In your boot.ini file, add /PATCHTPR to the boot line, eg: multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /noexecute=optin /fastdetect /patchtpr This may give you some speed increase depending on the CPU you are using. /PATCHTPR activates a feature in gplpv that patches the windows kernel to avoid using a certain hardware register (Task PRiority). Access to the register is very slow, and it is accessed very frequently. James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> > /PATCHTPR activates a feature in gplpv that patches the windows kernel > to avoid using a certain hardware register (Task PRiority). Access to > the register is very slow, and it is accessed very frequently. >And in case you were wondering, this also affects Windows 2003 sp1 and older. Windows 2003 sp2 does not access the TPR register at all and so does not need the patch. James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Thanks all for your answers. I''ll give the different options a try & post an update on the list asap Sylvain. James Harper a écrit :>> Hello, >> >> I''m new to Xen and after properly configured a couple of Linux based >> VMs, I''m giving a try to a Windows XP domU. >> >> Installation is going just fine, network performances are pretty good >> after installing the gplpv driver (1Gb link properly recognized), but >> opening a session and usage is very slow through RDP. > > In your boot.ini file, add /PATCHTPR to the boot line, eg: > > multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP > Professional" /noexecute=optin /fastdetect /patchtpr > > This may give you some speed increase depending on the CPU you are > using. > > /PATCHTPR activates a feature in gplpv that patches the windows kernel > to avoid using a certain hardware register (Task PRiority). Access to > the register is very slow, and it is accessed very frequently. > > 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
as a quick update, the /patchpr thing fixed the speed of the domU. Thanks! James Harper a écrit :>> Hello, >> >> I''m new to Xen and after properly configured a couple of Linux based >> VMs, I''m giving a try to a Windows XP domU. >> >> Installation is going just fine, network performances are pretty good >> after installing the gplpv driver (1Gb link properly recognized), but >> opening a session and usage is very slow through RDP. > > In your boot.ini file, add /PATCHTPR to the boot line, eg: > > multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP > Professional" /noexecute=optin /fastdetect /patchtpr > > This may give you some speed increase depending on the CPU you are > using. > > /PATCHTPR activates a feature in gplpv that patches the windows kernel > to avoid using a certain hardware register (Task PRiority). Access to > the register is very slow, and it is accessed very frequently. > > 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