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Re: Some questions about naming (newbie)
> 3. A LUN
WWN is at the SCSI LUN level, and can be used for
identifying > LUNs regardless of whether the underlying
transport is FC, parallel > SCSI, or iSCSI.
However, most FC devices do not support the LUN > WWN,
and use serial numbers, device IDs, and other mechanisms
to > correlate them. To do this, one must
implement device-type-specific > code.
>
Anyway, those were just a few observations that might help. Thank you -- they
do.
> On question 3, keep in mind that an INQUIRY is done at the
SCSI > level, and is independent of the SCSI transport mechanism
used. > Therefore, the VPD information would not return anything that
would > reflect an iSCSI identifier. The ability to return a LUN WWN
(from > (3) above) on this page really is a SCSI-level thing, and has
nothing > to do with FC other than that it shares the same address
format. I think i understand your point: A device might not be iSCSI only
-- it might also have FC, plain SCSI (what's the official name for that?)
interfaces, so the device doesn't necessarily know its node-name; that's the
interface's responsibility? I don't actually need a node-name -- any
identifying string will do. But the node-name is nice because the iSCSI
naming spec requires it (along with the actual LUN number) to uniquely
identify the LUN. That's something i don't know to be available through any
other specifi- cation. Am i right there?
> At any rate, in order to
connect to a SCSI device via iSCSI to do > the INQUIRY, you must first log
in to the target at the iSCSI level. > To do this, you would already have
the iSCSI name (formerly WWUI), > so you should already have the
information you need without the > inquiry data. Yes, but in order for
my (application-level) code to do that, it has to be aware that the transport
is iSCSI, and many OSs take great pains to hide that information from
application-level code. MS even tries to make ATA hard disks look like SCSI
(gag). So it would be nice if:
1. Table 111 of the SCSI Primary
Command set (T10 995d Rev. 11a) included an additional
identifier type "iSCSI node-name" 2. Devices supporting iSCSI were strongly
recommended (even though this can't be required for the reasons
discussed above) to report this identifier on VPD page
0x83.
> Mark A. Bakke > Cisco Systems > mbakke@cisco.com >
763.398.1054
Justin
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Last updated: Tue Sep 04 01:05:00 2001
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