On August 20, 2010, Nikolai K. Bochev wrote: > Could you try : > > 1. Share a folder from winxp > 2. From another box start copying a large file to the winxp share > 3. Observe loadavg on the kvm host > > Both with default settings and cache=none > > I was getting loadavg ~35 ( on a 2xXeon E5520 ) with the default setting > and read/write speeds around 20Mb/s . With cache=none the loadavg dropped > to ~3 and the speeds increased to 40Mb/s. > > The host is ubuntu 10.04. > The guest is ubuntu 10.04 with raw image as disk. >
I've since done some more testing, and while read access did seem to be better, write access is absolutely horrible with the defaults. with cache=none I at least get 40-50MB/s write, as well as read. so I'm happy enough. > From: "Thomas Fjellstrom" <[email protected]> > To: [email protected] > Sent: Friday, August 20, 2010 12:00:41 PM > Subject: Re: [virt-tools-list] Default use of caching on raw volumes > > After seeing this thread I tried to see what would happen with a windows xp > guest using lvm+virtio and changing the cache option to none. Performance > drops about 10-20MB/s. Whatever the default is, I get an average of 55MB/s > read according to hd-tune. With cache=none I get more like 35-40MB/s. -- Thomas Fjellstrom [email protected] _______________________________________________ virt-tools-list mailing list [email protected] https://www.redhat.com/mailman/listinfo/virt-tools-list
