On Fri, Mar 11, 2022 at 01:31:02PM -0800, Keith Busch wrote: > On Fri, Mar 11, 2022 at 01:04:35PM -0800, Luis Chamberlain wrote: > > On Fri, Mar 11, 2022 at 12:51:35PM -0800, Keith Busch wrote: > > > > > I'm starting to like the previous idea of creating an unholey > > > device-mapper for such users... > > > > Won't that restrict nvme with chunk size crap. For instance later if we > > want much larger block sizes. > > I'm not sure I understand. The chunk_size has nothing to do with the > block size. And while nvme is a user of this in some circumstances, it > can't be used concurrently with ZNS because the block layer appropriates > the field for the zone size. Many device mapper targets split I/O into chunks, see max_io_len(), wouldn't this create an overhead? Using a device mapper target also creates a divergence in strategy for ZNS. Some will use the block device, others the dm target. The goal should be to create a unified path. And all this, just because SMR. Is that worth it? Are we sure? Luis
