On 16/07/13 14:18, Rushikesh Jadhav wrote:
On Tue, Jul 16, 2013 at 3:26 PM, David Vrabel <david.vrabel@citrix.com mailto:david.vrabel@citrix.com> wrote:
On 15/07/13 20:44, Rushikesh Jadhav wrote: > Hi List, > > It seems that the xen balloon functionality for guest is not enabled in > CentOS 3.4.50-8.el6 xen kernel by default via centos-release-xen.x86_64 > repo. I think this should have been present since this extra Xen repo > needs to support as both Guest and Host (Dom0). The kernel is only intended for use as a dom0 kernel. We recommend the use of the existing 2.6.32 kernel for guests.Any idea for not using 3.4.50 as guest kernel ?
The specific 3.4 kernel provided as part of the Xen4CentOS project as a configuration selected for use as a dom0 kernel and thus it may not have guest-centric options (like ballooning) correctly configured.
Problem may be with CONFIG_XEN_BALLOON_MEMORY_HOTPLUG=y as well. What do you think ?
CONFIG_XEN_BALLOON_MEMORY_HOTPLUG=y is required to allow most Linux PV guests to balloon above their initial allocation. However, it is broken in some cases when enabled in a dom0 kernel and has been disabled.
As a workaround I would suggest starting all guests with an initial allocation that corresponds to the maximum they may ever use. You can then immediately balloon them down.
David