Re: LUN field in iSCSI Data PDU

[julian_satran@il.ibm.com]

Vengat,

The LUN field is mandated only if the Target Tag is valid (i.e., the data
is sent in response to a R2T).
This way you can get to "decentralize" the target activity as the tags can
be issued "locally" by the LUs.

Julo

"Venkat Rangan" <venkat@rhapsodynetworks.com> on 20/11/2000 20:38:23

Please respond to "Venkat Rangan" <venkat@rhapsodynetworks.com>

To:   "IP Storage Working Group" <ips@ece.cmu.edu>
cc:
Subject:  LUN field in iSCSI Data PDU




Section 2.8 specifies that the SCSI Data Header contains "LUN or Reserved
(0)" at offset 8-16 within the header. I am not clear under what
circumstandes it contains a LUN. Note that the LUN info was already sent in
an earlier SCSI CMD PDU. If a LUN is specified in SCSI Data PDU as well,
what is its relationship to the one sent in SCSI CMD?

If we look at Fibre Channel FCP_DATA framing, it does not include a LUN,
since the FCP_CMD has established the LUN for the exchange already.

Venkat Rangan
Rhapsody Networks Inc.
www.rhapsodynetworks.com