[CentOS-virt] Xen Balloon Driver on PVHVM CentOS6
david.vrabel at citrix.com
Tue Jul 16 09:56:14 UTC 2013
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.
> The kernel had to be recompiled with CONFIG_XEN_SELFBALLOONING.
> How can I request to make it default enable in centos repo ? or is there
> any reason to not have it default ?
We do not want self-ballooning enabled in the dom0 kernel. This option
is also not required for toolstack-directed ballooning.
> On Fri, Jul 12, 2013 at 7:42 PM, Rushikesh Jadhav <2rushikeshj at gmail.com
> <mailto:2rushikeshj at gmail.com>> wrote:
> Hi List,
> I'm trying to work out the balloon driver on CentOS6 HVM but it
> seems to be not working with default 2.6.32 or newer 3.4 kernel.
> Does balloon driver work on HVM linux guests with Linux Kernel 3.4
> from centos repo ?
> PV is fine and is able to balloon.
> My host is Xen 4.1.2 with dom0 as 3.4.46-8.el6.centos.alt.x86_64
> My guest is CentOS6.4 with kernel 3.4.46-8.el6.centos.alt.x86_64
> Please have a look at below guest logs,
> [root at hvmc6 ~]# uname -a Linux hvmc6 3.4.50-8.el6.centos.alt.x86_64
> #1 SMP Fri Jun 21 03:14:22 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
> [root at hvmc6 ~]# xenstore-ls memory initial-reservation = "1193984"
> initial-target = "1048576" static-max = "16777216" target =
> "1048576" dynamic-min = "1048576" dynamic-max = "1048576"
> memory-offset = "-258100"
> [root at hvmc6 ~]# dmesg | grep -i balloon xen/balloon: Initialising
> balloon driver. xen-balloon: Initialising balloon driver.
> [root at hvmc6 ~]# free -m total used free shared buffers cached Mem:
> 463 221 241 0 24 13 -/+ buffers/cache: 184 278 Swap: 9987 7 9980
It's not clear what sequence of toolstack operations you've done prior
to the above commands. Are you trying to increase or decrease the
amount of memory in the guest, what were the toolstack commands you used
and what is the initial guest configuration.
> When I try to set it manually from host, I get
> # xl mem-set 229 2049 xc: error: do_memory_op: WARNING: op=16 not
> converted to safe ioctls: Internal error
This (harmless) warning only occurs on XenServer hosts. What host are
you actually running?
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