On Fri, Nov 08, 2013 at 01:17:17AM +0000, Zhanghaoyu (A) wrote: > >> I read below words on the report of <KVM Live Migration: Weather > >> forecast (May 29, 2013)>, We were going to remove the old > >> block-migration code Then people fixed it > >> Good: it works now > >> Bad: We have to maintain both > >> It uses the same port than migration > >> You need to migrate all/none of block devices > >> > >> The old block-migration code said above is that in block-migration.c? > > > >Yes. > > > >> What are the reasons of removing the old block-migration code? Buggy > >> implementation? Or need to migrate all/none of block devices? > > > >Buggy and tightly coupled with the live migration code, making it hard to > >modify either area independently. > > Thanks a lot for explaining. > Till now, we still use the old block-migration code in our virtualization > solution. > Could you detail the bugs that the old block-migration code have?
Please use git log block-migration.c to see bugs that have been fixed. The basic problem is that block-migration.c hasn't been actively maintained or used much. My impression is that the newer block migration approach using drive-mirror now has more developer and testing focus (see libvirt if you're curious how drive-mirror can be orchestrated). Stefan
