> > I have been offered a very good deal on the controller in the subject,
and I
> > understand that it is supported by OpenBSD. Does anyone have any
experience
> > with it, and most important, any reason why I would _not_ want to use it
for
> > an OpenBSD server?
>

I've had one for a few years now and just recently exchanged it for a
Raidcore RC4852. I'm planning to build my OpenBSD PC around the 2400A but
haven't started yet so my experience is only from Windows.
It has been rock solid, no problems whatsoever and it supports JBOD, RAID0,
RAID1 and RAID5. I've seen better BIOS user interfaces though to create the
arrays but it's manageble. However, I bought it for its RAID5 capability but
the performance in RAID5 mode is lousy at best. Even with a maximum of four
HDs it's a lot slower than even one single HD attached to the motherboard. I
understood later that this is because the XOR engine is implemented in the
firmware and not the hardware. Some performance loss is also caused by the
SCSI-IDE bridge that Adaptec choosed to put on the controller (it's not a
native IDE controller) and the extra data writes generated by the parity in
RAID5 mode. I haven't tried the other RAID modes myself but judging from
benchmarks on the Internet, it doesn't perform much worse than any other
popular controller from Promise or Highpoint.
Great support from Adaptec on this adapter though. They haven't abandoned it
although it's rather old now. With the latest firmware upgrade it even
supports HDs larger than 137GB.

/PP