On Mon, Aug 8, 2011 at 3:47 PM, Avi Kivity <a...@redhat.com> wrote: > On 08/08/2011 05:46 PM, Avi Kivity wrote: >> >> Please provide documentation in docs/ of the compression format. >> >> IMO it should be disabled by default (with an option to disable it, via, >> sat, migrate-set-options, so we can migrate to older hosts). >> >> The protocol should allow XBZRLE to turn itself off if it detects that it >> isn't effective. >> > > IOW, this should be part of the standard migration protocol, not some side > option that is enabled if the user remembers. It should not be mutually > exclusive with future migration extensions, including compression.
This is an attractive option. With some polish maybe XBZRLE could be integrated as a default option that does not degrade performance. Adding features that require user configuration isn't worthwhile because they won't be used or they'll be misused - let's not make QEMU more complicated if it can be avoided. If there is no way to make XBZRLE automatic then I think it should live outside QEMU because it will be a niche feature that relatively few will use but adds complexity to migration. Stefan
