We have some test servers running SLES11SP1 and we''ve updated to the latest kernel from Novell: 2.6.32.13-0.5-xen Since running the updates on these servers our xen ballooning parameters are not working. Because of memory problems in the past we set dom0 to 2048 meg of ram in grub and set the following parameters in /etc/xen/xend-config.sxp: (dom0-min-mem 2048) (enable-dom0-ballooning no) Looks like this kernel is ignoring those parameters because I had to turn ballooning back on before we could start any VMs. I was going to open a ticket with Novell, but thought I''d ask if anyone has seen this? Maybe disabling ballooning is not the way to go anymore, anyone have opinions on that? We used to run out of memory a lot, even though there was plenty free. Disabling ballooning seemed to make things more stable at the time. Any suggestions are appreciated. Thanks, James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
You need to make sure that you set the dom0_mem parameter at boot time. Without that parameter what you''re basically doing is assigning all of your available RAM to your dom0, then telling dom0 that memory cannot be dynamically changed, but that it must be at least 2048M. This means that there is 0 free memory for domUs. So, set the dom0_mem boot parameter, and keep the parameters configured as you have them below in the xend-config.sxp file. Then start some domUs. You can also look at "xm info" and see the free memory parameter and verify that that shows the amount of memory you expect to be available for domUs. -Nick>>> On 2010/08/05 at 10:50, James Pifer <jep@obrien-pifer.com> wrote: > We have some test servers running SLES11SP1 and we''ve updated to the > latest kernel from Novell: 2.6.32.13-0.5-xen > > Since running the updates on these servers our xen ballooning parameters > are not working. Because of memory problems in the past we set dom0 to > 2048 meg of ram in grub and set the following parameters > in /etc/xen/xend-config.sxp: > (dom0-min-mem 2048) > (enable-dom0-ballooning no) > > Looks like this kernel is ignoring those parameters because I had to > turn ballooning back on before we could start any VMs. > > I was going to open a ticket with Novell, but thought I''d ask if anyone > has seen this? > > Maybe disabling ballooning is not the way to go anymore, anyone have > opinions on that? We used to run out of memory a lot, even though there > was plenty free. Disabling ballooning seemed to make things more stable > at the time. > > Any suggestions are appreciated. > > Thanks, > James-------- 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 Thu, 2010-08-05 at 13:29 -0600, Nick Couchman wrote:> You need to make sure that you set the dom0_mem parameter at boot time. Without that parameter what you''re basically doing is assigning all of your available RAM to your dom0, then telling dom0 that memory cannot be dynamically changed, but that it must be at least 2048M. This means that there is 0 free memory for domUs. So, set the dom0_mem boot parameter, and keep the parameters configured as you have them below in the xend-config.sxp file. Then start some domUs. You can also look at "xm info" and see the free memory parameter and verify that that shows the amount of memory you expect to be available for domUs. > > -NickYeah, we have that set too. A reboot seemed to resolve it, but I don;t know why it happened in the first place. Thanks, James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 James Pifer [05.08.2010 18:50]:> We have some test servers running SLES11SP1 and we''ve updated to the > latest kernel from Novell: 2.6.32.13-0.5-xen > > Since running the updates on these servers our xen ballooning parameters > are not working. Because of memory problems in the past we set dom0 to > 2048 meg of ram in grub and set the following parameters > in /etc/xen/xend-config.sxp: > (dom0-min-mem 2048) > (enable-dom0-ballooning no) > > Looks like this kernel is ignoring those parameters because I had to > turn ballooning back on before we could start any VMs. > > I was going to open a ticket with Novell, but thought I''d ask if anyone > has seen this? > > Maybe disabling ballooning is not the way to go anymore, anyone have > opinions on that? We used to run out of memory a lot, even though there > was plenty free. Disabling ballooning seemed to make things more stable > at the time. > > Any suggestions are appreciated.I don''t know if you''re interested in the opinion that SAP has. They recommend to not use more than 1 gig of RAM in dom0 (since there should be no services running in dom0, you better create a new domU for those) and to disable ballooning, since this may cause errors. Besides, the SAP software claims its memory directly when starting and so there is no need for further ballooning for their domUs ;-) I use dom0_mem=1024M in the kernel line in /boot/grub/menu.lst and I added it in /etc/sysconfig/bootloader to the XEN_KERNEL_APPEND variable, so every kernel update will still use this value. HTH Werner -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.15 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org/ iEYEARECAAYFAkxbo7cACgkQk33Krq8b42NuZgCcCOZkci8QqkD3wALOV23AZ4my HFYAnAiwyABYvgGZwPzcuqPsNynR644L =0Nkz -----END PGP SIGNATURE----- _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users