[openib-general] Managing SRP devices via iSCSI ?

[Yaron Haviv]

________________________________________
>From: openib-general-bounces at openib.org
[mailto:openib-general->bounces at openib.org] On Behalf Of Rick Frank
>Sent: Monday, September 19, 2005 10:02 PM
>To: openib-general at openib.org
>Subject: [openib-general] Managing SRP devices via iSCSI ?
>
>One key argument I've heard in favor of iSER vs SRP is that iSCSI (top
>level 
>iSER driver) has a very strong management infrastructure - as it is
fairly 
>mature.
>
>However, iSER seems to be just gaining steam in terms of direct
attached 
>storage supporting this protocol .vs. SRP.
>
>Would it not be possible to implement some glue between SRP and iSCSI
to 
>allow for the discovery and management of SRP devices ?

Rick,

The question is why bother with a new approach when iSER is what you
just suggested ?

a. After all iSER transactions are similar to SRP ones (derived from
SRP) with few enhancements in favor of iSER (SRQ, FMR, MC/S, immediate,
recovery,..).

b. iSER header and naming convention is derived from iSCSI, where as SRP
naming and header structure is different forcing redundant translation
between the two, and some functionality that wouldn't be possible such
as Portals, MC/S, ACA, etc', makes more sense to just use the iSCSI base
header format (like iSER does).

c. iWarp guys that now join OpenIB will never use this non standard, IB
specific SRP/iSCSI hybrid but rather the real iSER. 

d. SRP which was initially defined in T10 lost all its momentum in T10
(last SRP meeting was 2 years ago), not sure how you will standardize
your proposal, where iSER is in IETF (integral part of iSCSI/IPS) and
serves IB & iWarp, guaranteeing its momentum will grow, and it will be
enhanced over time.

So I believe overall it's simpler to move SRP implementations to iSER,
(some vendors already wisely do that) than somehow define a non standard
SRP with iSCSI management, after all iSER is just what you propose
(improved SRP with iSCSI services), and is already defined (last call in
IETF).

By the way I wouldn't deduct from few early experiments of SRP storage
in the market a whole lot on SRP adoption among key storage vendors or
on their future plans.

If you are interested in more details on iSER let me know 

Yaron