Thanks, do you own any other Sun hardware? What would you recommend for someone who’s never had a Sun system?
My only other one is a Sun Fire T1000. It's a nice system as well, though a generation or so older and, being a 1U system, louder as well. My guess is the fan speeds are higher on the 1U servers to compensate for the more tightly packed chassis. The T1000 is a real howler and makes even this seem tame in comparison.
Either one would be a good choice. They are widely available and fairly cheap right now.
Some scattered thoughts:
There is a noticeable performance improvement with the UltraSPARC T2 vs the older T1. Both of these workhorses are really built for highly concurrent databases, rather than single core performance. Having 32 cores is cool, but doesn't translate to the performance you may expect.
As a full length 2U server, the T5220 is massive, while the T1000 is a far more manageable half-length 1U. If you want a 1U system, but want the UltraSPARC T2, look for a T5120.
The T1000 had a power supply issue when i got it which is apparently common, so maybe get an extra one just in case.
I use Sun SAS drives in mine because they seem pretty decent and are inexpensive, but any brand will work.
Not all systems have a CD/DVD drive. My T1000 does not, so I used the T5220 to install OpenBSD via CD on both hard disks, then just pulled one out and stuck it in the T1000.
Get a couple USB to RJ45 serial cables. I lose the damn things on a regular basis.
Get familiar with Open Firmware because you may have to fiddle with it to get your OS to boot. Since these are secondhand, the previous owners probably had it setup already for their environment. Lots of docs for these servers are available online so this is fairly easy to get going.