At work I have ~20 XRAIDS. First of all, I feel your pain :)
Download the RAID Admin tool from Apple. It's written in Java, and you can run it under Linux pretty easily. (as in, "java (whatever).jar") I would strongly suggest not letting it remember the IPs of all of your XRAIDS, it seems to query them all periodically, without letting the GUI update (this could be a problem with the old version of Java I'm running it on too. Try it and let me know?)
It will ask you for your read and write passwords when it needs them, and can save them. If you just unboxed the things, their passwords are "public" and "private" respectively. I suspect that it's all SNMP under the hood, but I haven't verified that.
If you're not running the latest firmware, upgrade ASAP. The older one that all of mine came with had a bug where it would occasionally forget how to use the Ethernet port. Being that you admin it over that Ethernet... bad.