Hi all,
How can I manage automatically memory ballooning under a kvm host
(C5.6 and future C6)?? For example if I define a kvm guest to boot up
with 512MB of RAM and I have configured 1GB as a maximum memory for this
guest, how can I allocate this memory when guest will need it??
And the opposite question, can memory balloon be deallocated?? And is
it possible to do this automatically or is an error to do this??
Thanks.
--
CL Martinez
carlopmart {at} gmail {d0t} com
carlopmart wrote on 04/23/2011 05:04 PM: ...> How can I manage automatically memory ballooning under a kvm host > (C5.6 and future C6)??Looks like you got an answer to your nearly identical post on rhelv6-list: https://www.redhat.com/archives/rhelv6-list/2011-April/msg00055.html Phil
----- Original Message -----
| Hi all,
|
| How can I manage automatically memory ballooning under a kvm host
| (C5.6 and future C6)?? For example if I define a kvm guest to boot up
| with 512MB of RAM and I have configured 1GB as a maximum memory for
| this
| guest, how can I allocate this memory when guest will need it??
|
| And the opposite question, can memory balloon be deallocated?? And is
| it possible to do this automatically or is an error to do this??
|
| Thanks.
|
| --
| CL Martinez
| carlopmart {at} gmail {d0t} com
| _______________________________________________
| CentOS-virt mailing list
| CentOS-virt at centos.org
| http://lists.centos.org/mailman/listinfo/centos-virt
No you cannot do it automatically. It must be scripted and reboots are
required. Under any 5.x branch it is simply not possible as not all information
needed to be provided may be available. Can't remember where I read that,
but it was quite recent. Check the RH documentation
--
James A. Peltier
IT Services - Research Computing Group
Simon Fraser University - Burnaby Campus
Phone : 778-782-6573
Fax : 778-782-3045
E-Mail : jpeltier at sfu.ca
Website : http://www.sfu.ca/itservices
http://blogs.sfu.ca/people/jpeltier
> ?And the opposite question, can memory balloon be deallocated?? And is > it possible to do this automatically or is an error to do this??I think your understanding of ballooning may be backwards. The purpose of the balloon driver is to give the host system a way of recovering memory from the guest when the demands on the host's physical memory exceed the amount available. The balloon inflates within the guests forcing them to swap or take other memory management measures. When the pressure on the host eases the balloon deflates automatically. -- Drew "Nothing in life is to be feared. It is only to be understood." --Marie Curie
> And the opposite question, can memory balloon be deallocated?? And is> it possible to do this automatically or is an error to do this?? I think your understanding of ballooning may be backwards. The purpose of the balloon driver is to give the host system a way of recovering memory from the guest when the demands on the host's physical memory exceed the amount available. The balloon inflates within the guests forcing them to swap or take other memory management measures. When the pressure on the host eases the balloon deflates automatically. Sorry Drew, but I don't understand the use of balloon driver like you explains. According to RedHat's docs: "The balloon driver allows guests to express to the hypervisor how much memory they require. The balloon driver allows the host to efficiently allocate memory to the guest and allow free memory to be allocated to other guests and processes. Guests using the balloon driver can mark sections of the guest's RAM as not in use (balloon inflation). The hypervisor can free the memory and use the memory for other host processes or other guests on that host. When the guest requires the freed memory again, the hypervisor can reallocate RAM to the guest (balloon deflation). " http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Virtualization/para-virtdrivers.html (The balloon driver) I don't see in this doc any reference to "balloon driver is to give the host system a way of recovering memory from the guest when the demands on the host's physical memory exceed the amount available" -- CL Martinez carlopmart {at} gmail {d0t} com