On Tue December 15 2009, Avi Kivity wrote: > On 12/13/2009 07:16 PM, Thomas Fjellstrom wrote: > >> Linux usually keeps very little RAM free (it's kept as cache). So > >> there has to be some action on the part of the host to get the guest > >> to free things. For Windows guests you can use ksm to reclaim free > >> memory (since Windows will zero it). > > > > I'm waiting for 2.6.32 to hit Debian Sid before I start playing with > > ksm (I don't think its in 2.6.31). > > > > The problem is it should be automatic. The balloon driver itself or > > some other mechanism should be capable of noticing when it can free up > > a bunch of guest memory. I can't be bothered to manually sit around and > > monitor memory usage on my host so I can then go into virt-manager to > > reduce memory to each guest. > > That should be pretty easy though it will have an effect on guest > performance. >
As long as its only done after an appropriately long idle period (ie: theres been X MB's free for a long time, give it back), I can't see it harming performance too much. At least not more than setting ram too low when manually (de)ballooning memory. -- Thomas Fjellstrom tfjellst...@shaw.ca -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
