🚀 go-pugleaf

[Steve Wampler]
# We are considering buying some DECstation 3100's for use in
# a network.  Although essentially diskless, I like the idea
# of having a small 'paging' disk in each.

Excellent idea.  Never has a workstation needed local (i.e., fast) paging
as much as this one -- you've got more horsepower than an 8800 and slightly
larger executables, so you end up with this burning itch to run 35 things
on the machine all at the same time just to see it go slow.  24MB isn't
enough memory to hold everything it takes to make the CPU actually bog down.
Therefore you do a little paging now and then, and if you're waiting for NFS
to give you the data (DEC doesn't use ND, never has, never will), you'll be
very sad and somewhat frustrated.

# Dec sells a 104MB 3.5in disk for just this purpose.  I was wondering
# what other options might be (and for how much).  The controller is SCSI,
# so I assume that most SCSI drives would work, but I know *nothing* about
# 3.5in SCSI drives.

"Most" is the key word, and it's wrong.  The proper word is "some".  SCSI is
not a perfect standard and there are many imperfect implementations of it.  I
understand that we (DEC) had to test several SCSI drives before we found one
that worked "properly", whatever that means.

# I know CDC makes a 16.5ms 100MB 3.5in drive, for example,
# but haven't heard of a SCSI version of it.

I have not heard of a NON-scsi version of it.  Those are great drives; I'll
bet they work "properly", whatever that means.  I've also heard some good
things about Fujitsu 3-inchers.

# If you know of any that are reasonable (and I assume that,
# for paging, speed is pretty important), please email me.

The SCSI interface will push synchronous SCSI data down the wire at 4
MB/sec, so make sure your drive has fast sychronous support.  Some drives
either don't have synchronous mode or have it but run about 1 MB/sec.

# By the way, I have one piece of paper from DEC telling me
# the 3100 enclosure can take two 1/2ht 3.5in drives, but
# all the other pieces of paper only mention putting one
# such beast internally.  Anyone know for certain?

There's room in the box for 2 half-height 3.5-inch drives, but the power
supply may or may not have the juice to run two of them if they're hungry
and you've got a full 24MB.  Check, as Ricky Palmer suggests, with your
salescritter; don't be surprised if they say "only one drive is supported",
but get your techies to look at the power supply with a watt-meter and at
the specs for power-supply and your proposed extra drive; you may end up
(no promises and please don't quote me) voiding your warrantee and/or
service contract, but there may be enough power in there to do everything.

Disclaimer: it's 1:30 in the morning, and I'm sure my manager doesn't know
where I am or what I'm doing; I'm sure he will disavow all knowledge of my
activities if you call him.
--
Paul Vixie
Work:    vixie@decwrl.dec.com    decwrl!vixie    +1 415 853 6600
Play:    paul@vixie.sf.ca.us     vixie!paul      +1 415 864 7013