On Fri, Mar 06, 2015 at 03:48:40PM -0500, Mo Morsi wrote: > > On 03/06/2015 12:00 PM, Kashyap Chamarthy wrote: > >On Thu, Mar 05, 2015 at 11:48:08AM -0700, Mike Ruckman wrote: > >>Fellow cloudies, > >> > >>The recent builds of our images are v3 qcow2 (also known as qcow3). > >>This presents a problem for our testing, since the openstack instances > >>we have access to don't support v3, only v2. The only difference > >>between v2 and v3 are some performance enhancements - > >Right, just some details on the said performance enhancements in QCOW2 > >v3 format, from my notes (about a year old) from an earlier discussion > >w/ some QEMU developers, the two new features in v3 of QCOW2: > > > > (1) lazy_refcounts -- A performance optimization interesting only when > > using 'cache=writethrough'. Useful when guest crashes or powers off. > > (2) Zero clusters -- Useful for (disk) image streaming over slow > > networks. > > > > > > Perhaps of interest: > > http://talk.manageiq.org/t/qcow-image-format-versions-2-3-analysis/491 Yep, it is interesting. Thanks for the pointer, Mo. -- /kashyap _______________________________________________ cloud mailing list cloud@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/cloud Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
