On Tue, 15 Feb 2000, Matthew Dillon wrote:
> Not with LVD. The whole point was to be able to have longer SCSI
> busses.
>
> LVD allows SCSI bus cable lengths up to 25 meters. With 16 devices
> the limit is 12 meters. That's 36 feet, folks!
Which isn't really that much, once you get to the lots of busses point. It
gets hard to physically fit everything. While you can put 16 devices on a
SCSI bus, you can't do that and get highest performance out of them.
Depending on what the data access model is, I have found between four and
eight devices is best. I helped build a database server with just under
200 disks. If we hadn't been using hardware that let us put I/O controllers
10 meters from the CPU cabinet, we would have had a hard time building the
machines with all the busses under the length limit. This was a duplex
machine, so that's an additional problem. Of course, today I'd do it with a
lot fewer disks.
David
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