[Figured it was about time to change the subject line...]
Speaking of hardware design, I've got a few misc. questions and comments.
These are geared towards building servers for remote use that are *not*
routers, but rather light- to medium-load webservers and the like.
Does anyone know of a *small* rackmount case for PCs? By this I mean one
that doesn't chew up quite so much vertical room as the usual boxes.
Does anyone know where to get a CPU card with integrated SCSI and video?
Alternatively, integrated SCSI and ethernet. I know about the PEAK 520S.
TJLS claims that it's got serious problems, and even if it does work, it
uses the SIS chipset, and thus loses big on memory access. I want something
that can boot NetBSD or BSDI.
One of the annoying problems using an intel box instead of a sun is that
there's no real console. If it dies, the only way to kick it remotely is
with a remote-control power switch. These are expensive and unwieldy, not
mounting nicely in racks.
In lieu of a real remote console like the one I described in a recent message,
Thor and I cooked up the notion of a user-mode demon that tickles a watchdog
timer every few seconds. (This is better than putting it in the kernel or
init, for a whole lot of reasons.) This will at least deal with the need to
reset a box when it dies. But I don't know where to get ISA cards that are
just watchdog timers (many CPU cards do come with timers built in). I'll be
doing some research today but if anyone knows where to get them, or has any
experience using them, I'd love to hear about it.
BTW, Thor's already gotten such a demon running under SCO. Doing it on NetBSD
and other Unixes looks to be trivial.
Lastly, I've seen this really neat rackmount chassis from Multitech. It's
got 22 ISA slots, severable into up to 9 parts, and enough drive bays to
actually run 9 separate servers. If you're looking for maximal density it
seems like a good bet. The only problem I can see is that you'll need CPUs
with both SCSI and viseo on board (thus my first question) unless you're
willing to run on IDE drives. I figure that for light or medium-use servers,
ethernet over ISA should be fine.
To really make this thing smooth, you'd want a box that can switch a floppy
cable nine different ways, since there's only room for one floppy in the case.
This doesn't seem very hard, conceptually, but I don't know of anyone who
makes such a device. I wonder if any existing switch could be adapted to
the purpose? I don't remember how many pins are actually used by one floppy,
but I suspect less than 25. If so, there are true 25-line switches available
that might do the job. (Black Box has 6-to-1 25-pin switches for $90, and I'm
sure they could do a 9-1 if you asked, though at a typically high price. I
don't know if the floppies could stand the noise caused by all the cable
changes. And you'd need DB-25 to floppy adaptor cables.)
MultiTech's working on a PCI model, too, but I don't know anything about it.
All other things being equal, this would allow you to use a CPU card with
enet and video, since running SCSI over PCI isn't the lose that it is over
ISA.
/a
