Hi Jason,
> Are there any Linux users out there using the likes of
> RAID'ed-NBD, CODA or
> Intermezzo for a similar effect?
> The NBD (network block device) looks interesting, it allows
> you to mount a remote raw partition - so you can effectively
> RAID over the network.
I'd recomend drbd over a nbd + raid solution:
* drbd knows to read from local device only so performance is generaly better
* it deals nicely with disconnect / reconnect scenarios.
I've used drbd in real-life configurations with linux FailSafe and with
heartbeat as cluster managers, works quite nicely once you get it running.
Problems with drbd:
* current version doesn't like SMP
* works at block level, so speed for a full synchronisation depends on
filesystem size, not just used space.
* resync speed limited to about 4MB/sec - limit aplies only for resync, not
for normal read/write access.
have a look at http://www.linbit.com/en/ for more information.
Bye, Martin