Re: iSCSI question

["Julian Satran" <Julian_Satran@il.ibm.com>]

Sharam,

You may want to go over the recovery chapter.
It has detailed answers to all your questions.
The superset/subset is based on functions you need for the next level.

Session recovery drops real recovery to SCSI.
Command recovery recovers from individual command errors without 
changing connection and the highest enable you to switch to a new connection and
continue commands there.

2 requires everything in 1.

Julo

Shahram Davari <Shahram_Davari@pmc-sierra.com> Sent by: owner-ips@ece.cmu.edu 08/07/2002 05:17 PM

To:        ips@ece.cmu.edu         cc:                 Subject:        iSCSI question

Hi,

I have a question regarding the hierarchy of error recovery.
Section 6.13 mentions the hierarchy as:

2: Connection recovery
1: Digest failure recovery
0: Session recovery

And it states that the higher levels are a superset of the
lower levels and that the level of complexity increases from 0->1->2.

Couple of questions:

1) How is digest failure recovery done? by retransmission of PDUs?
2) Why is the connection recovery a superset of session recovery
and more complex?
3) It seems to me the order should be:

2: Session recovery
1: Connection recovery
0: Digest failure recovery


I appreciate any insight.

Thanks,
-Shahram