Asymetric Assumptions

["Mark A. Carlson" <mark.carlson@sun.com>]

In many of the discussions that I have seen on this list, there
seems to be an unwritten assumption running through the threads
that initiators are hosts with lots of memory and resources and
targets are storage devices with restrained resources such as 
memory that need negotiation of the protocol parameters as a
result.

I would caution against making the protocol too asymmetric in this
regard as we would like this protocol to work between storage 
devices as well as between hosts and storage devices. This would
be used, for example, in a hostless back scheme or in a situation
where one storage device handles mirroring to other storage devices
itself.

In one case, for example, an initiator's read might actually be
committing the blocks to storage such as in a recovery from tape
situation. 

I think that the requirements document adequately describes
the requirements in this area, but we just need to be careful in
our thinking during protocol discussions that the assumptions that
we make do not cause the protocol to become asymmetric with regards to
initiators and targets. So far this hasn't been the case.

Thanks,

-- mark