On Mon August 17 2009, Avi Kivity wrote: > On 08/17/2009 01:49 PM, Thomas Fjellstrom wrote: > > One thing I found odd about kvm's ballooning is that it actually seems to > > change how much ram the guest has. I really didn't expect "free -m" to > > report that the guest only had 64M ram after I manually ballooned the > > ram. I was however expecting it just to free ram it wasn't using in the > > host. To me, it just doesn't seem to be the same thing. now it'll start > > swapping at 64M ram instead of just reallocating the ram it used to have. > > You expectations aren't realistic. kvm never allocates the ram the > guest doesn't use in the first place. Really? So htop is lying to me then? I gave 1G ram to a kvm linux guest using virtio (disk, net, ballooning), and RES clearly said 1G, and VIRT actually said somewhere around 1.3 to 1.6G. It stayed that way for over a day, and the guest did nothing the entire time. I know the kernel lies a little bit about ram usage, but it seems at least with kvm, the ram is in use when it says it is, while with vmware, it usually isn't. > Ballooning just the "free" > memory is pointless since it's usually a very small amount. > It may be worthwhile for the guest to give up that memory voluntarily > though. -- Thomas Fjellstrom tfjellstrom@xxxxxxx -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
