On Wed, 2007-08-15 at 11:07 +0300, Avi Kivity wrote: > Farkas Levente wrote: > > this rise another question if swapping will be used the it moves the > > guest memory to the guest's swap or the host's swap? if to the host's > > swap then this implies i should have to allocate large enough swap for > > the host. ie. even if i give only 256mb to the host still have to gives > > 6-8GB swap partition to the host. > > > > Yes, when swapping is implemented then guest memory will be swapped to > the host swap. Of course, if the guest has its own swap file, then it > will swap to the guest's swap independently.
And to clarify: FYI, I believe the guest-swap option should actually work today. If you assign a partition as a swap device in the guest it should use it. kvm-host will simply see it as disk io as any other. This is in contrast to the host-swap and/or balloon driver which is still a work-in-progress. On thing that is interesting about this (to me) is that, in a way it kind of is a "poor mans" swap for the guests memory on the host. E.g. you could give your guests a really small amount of "physical" ram (say, I dunno, 64MB/ea) and a large swap file (say several gigs). Since the disk-io emanating from the guest would likely be mediated by the hosts buffercache, its kind of like you just gave the guest a large chunk of (indirectly accessible) pageable ram. OTOH, virtualized disk-io is pretty slow compared to bare-metal io. As I said, this is a "poor mans" solution ;) What it really comes down to is: does having emulated disk-io to a buffercache offer adequate performance for your applications running in the guest? If so, this may be a good interim solution to get a larger number of guests running on a given host with "dynamic ram". Regards, -Greg ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
