On Wed, Jul 18, 2012 at 08:42:21AM -0500, Anthony Liguori wrote: > > If you add support for a new command, you need to provide userspace > a way to disable this command. If you change what gets reported for > VPD, you need to provide userspace a way to make VPD look like what > it did in a previous version. > > Basically, you need to be able to make a TCM device behave 100% the > same as it did in an older version of the kernel. > > This is unique to virtualization due to live migration. If you > migrate from a 3.6 kernel to a 3.8 kernel, you need to make sure > that the 3.8 kernel's TCM device behaves exactly like the 3.6 kernel > because the guest that is interacting with it does not realize that > live migration happened. I don't think these strict live migration rules apply to SCSI targets. Real life storage systems get new features and different behaviour with firmware upgrades all the time, and SCSI initiators deal with that just fine. I don't see any reason to be more picky just because we're virtualized. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
