[stgt] Why LUN0?

[ronnie sahlberg]

REPORTLUNS needs this. You must present a LUN 0 that can respond to
REPORTLUNS so that an initiator can discover which LUNs are available.

I think this is part of SAM for SCSI-3.


Without a LUN:0   your initiator might either not be able to access
any LUNs at all on your target,
or if you are lucky/unlucky (I dont really know which,  both options
are highly undesireable)  it might fall back to old style discovery
and
spin for many many minutes in a "try to talk to each LUN from LUN 0 to
LUN <huge number> one at a time to see which ones exist"
everytime you reboot and the host needs to re-scan the bus.



regards
ronnie sahlberg

On Wed, Nov 28, 2012 at 5:53 PM, Braun, David <David.Braun at drs.com> wrote:
> I'm trying to understand the need for LUN0. Is this required by the
> iSCSI standard (RFC-3720) or is it an artifact of the implementation? As
> a test I modified a copy of tgtd and tgtadm to allow the "-force"
> argument to the logicalunit delete function and it seems to work. BUT I
> must confess I'm ignorant of what the ramifications could be. Could
> someone explain the need for LUN0 or why I shouldn't be too surprised
> when this hack blows up in my face?
>
> Thanks
>
> Dave
> --
> To unsubscribe from this list: send the line "unsubscribe stgt" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe stgt" in
the body of a message to majordomo at vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html