>On 08/18/2010 09:23 AM, Daniel P. Berrange wrote: >> >> Previously when anyone has suggested setting cache=none for QEMU, >> other people have appeared with test results showing that other > > Care to provide references? I've yet to find a single report where > caching provides better performance with VMs stored on raw volumes > except for the use of writeback which is not recommended for anything > where data integrity is concerned. My suggested change improves > performance without risking data integrity.
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
