So I've been reading a lot about iSCSI - mostly positive (practical and pragmatic) but a few negative (largely academic or have enough money to go with Fibre Channel).

I suspect people had their doubts when moving from hubs to switches and 10mb to 100mb (coax to utp was a no-brainer so there was no doubt there :-)

Theres an interesting Usenix presentation with a slide on Differences Between NFS and iSCSI.

It does compare a transport mechanism with a distributed file system though. Confusing.

If you use Oracle over NFS why use a SAN if you can get away with a lower cost NAS ? Then again NFS is Unix-centric and you can't do Windows specific stuff beyond simple file-sharing with NAS (eg SQL, Exchange). Many DBA's seem to dismiss or deride Oracle over NFS while quite a few seem to think its a great way to go (although it would be good to read a practical unbiased example that wasn't from a SAN vendor).

The results of the benchmarking in the paper do seem to favour iSCSI in situations where data is not shared between systems and in meta-data intensive applications.

There also seems to be some debate about the merits of using a TOE adaptor in terms of adding yet another layer of complexity between your application server and its data. On top of this there seems to be a small but growing market for WAFS adding yet another layer to your LAN/WAN.

I guess iSCSI has been around for a few years now which in IT terms means it should have achieved a certain level of maturity which should allay any fears . . .

Useful benchmarking tool - IOMeter - ex Intel but now Open Source.

Use it to simulate load and test performance on storage devices (local, NAS or SAN).

Interesting article on how it is used in performance testing iSCSI over a Cisco MDS 9000-series Multi-protocol Switch.