On Tue, Jun 20, 2017 at 04:14:12PM +0200, Paolo Bonzini wrote:
We have four policies:
higher LUNs in lower targets win
LUN0 in all targets win
LUNs up to N and bootable ones in all targets win
(2) causes regressions so it's worse. (3) and (4) don't.
Because the common case is "not enough disks to trigger the issue", I think it's appealing to have no limit on LUNs (3); the disadvantage is the parallel multi-controller case.
The "and bootable ones" clause in (4) is nifty, and even "LUN0 and bootable nonzero LUNs" could be a good compromise. However, I'm not sure which higher-level management tools (OpenStack, oVirt, Virtuozzo) let you customize the boot order and how easily.
Alas, none of these options seem appealing to me.
If virtio-scsi didn't need to allocate any space in the f-segment, does this problem go away in practice?