Okay... a brief expansion on the previous e-mail.
1. While 8192 UDP xfer size is default in the imminently poised 5.3 release, the FDDI driver changes to address the hang are in place...
So, if you couple that to point 2 below, you can safely increase the xfer size to 32768 per my previous e-mail (modulo the comments about potentially performance challenged client NICS, where I would expressly worry about SGI Challenge or Challenge XL 100BaseT cards).
2. From my buddy, Devi (on the "new" Sun FDDI card):
In the filer - We did not handle one case where the device stopped transmitting while everything else was fine with it. Whenever we turn on 32K xfer size over UDP, and NPI cards are used in the clients, the FDDI device went into a state where it refused to transmit.
Clients with Cresendo cards talking to servers with NPI cards with old drivers failed similarly.
After a lot of experiments by the QA folks, we identified that NPI FDDI cards with drivers prior to "nf SBus FDDI Driver v2.05" did cause this.
If our customers can make sure that they do not have NPI cards with drivers prior to "nf SBus FDDI Driver v2.05", they can turn on 32K NFS/UDP xfers.
have a beer, beepy