AW: Largest file system being synced

[Martin Bene]

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