On Thu, 5 Apr 2018 17:43:46 -0600 Tim Walker <tim.t.walker@xxxxxxxxxxx> wrote: > On Tue, Apr 3, 2018 at 1:46 AM, Christoph Hellwig <hch@xxxxxxxxxxxxx> > wrote: > > On Sat, Mar 31, 2018 at 01:03:46PM +0200, Hannes Reinecke wrote: > >> Actually I would propose to have a 'management' LUN at LUN0, who > >> could handle all the device-wide commands (eg things like START > >> STOP UNIT, firmware update, or even SMART commands), and ignoring > >> them for the remaining LUNs. > > > > That is in fact the only workable option at all. Everything else > > completly breaks the scsi architecture. > > Here's an update: Seagate will eliminate the inter-LU actions from > FORMAT UNIT and SANITIZE. Probably SANITIZE will be per-LUN, but > FORMAT UNIT is trickier due to internal drive architecture, and how > FORMAT UNIT initializes on-disk metadata. Likely it will require some > sort of synchronization across LUNs, such as the command being sent to > both LUNs sequentially or something similar. We are also considering > not supporting FORMAT UNIT at all - would anybody object? Any other > suggestions? > Ah. Far better. What about delegating FORMAT UNIT to the control LUN, and not implementing it for the individual disk LUNs? That would make an even stronger case for having a control LUN; with that there wouldn't be any problem with having to synchronize across LUNs etc. Cheers, Hannes