On Thu, May 12, 2011 at 12:39:22PM +0200, Juan Quintela wrote: > "Shribman, Aidan" <aidan.shrib...@sap.com> wrote: > >> On Wed, May 11, 2011 at 8:58 AM, Shribman, Aidan > >> <aidan.shrib...@sap.com> wrote: > >> > From: Aidan Shribman <aidan.shrib...@sap.com> > >> > > >> > [PATCH] Add warmup phase for live migration of large memory apps > >> > > >> > By invoking "migrate -w <url>" we initiate a background > >> live-migration > >> > transferring of dirty pages continuously until invocation > >> of "migrate_end" > >> > which attempts to complete the live migration operation. > >> > >> What is the purpose of this patch? How and when do I use it? > >> > > > > The warmup patch adds none-converging background update of guest > > memory during live-migration such that on request of live-migration > > completion (via "migrate_end" command) we get much faster > > response. This is especially needed when running a payload of large > > enterprise applications which have high memory demands. > > We should integrate this with Kemari (Kemari is doing something like > this, just that it has more requirements). Isaku, do you have any comments?
Yochi and Kei are familiar with Kemari. Not me. Cced to them. > > BTW, what loads have you tested for this? > > if I setup an image with 1GB RAM and a DVD iso image, and do in the > guest: > > while true; do find /media/cdrom -type f | xargs md5sum; done > > Migration never converges with current code (if you use more than 1GB > memory, then all the DVD will be cached inside). > > So, I see this only useful for guests that are almost idle, and on that > case, migration speed is not the bigger of your problems, no? > > Later, Juan. > -- yamahata
