Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ukma!husc6!rice!sun-spots-request
From: aad@stepstone.com (Anthony A. Datri)
Newsgroups: comp.sys.sun
Subject: Emulex MD21 vs. Adaptec ACB4000
Keywords: Hardware
Message-ID: <8903182349.AA00475@count.stepstone.com>
Date: 4 Apr 89 05:23:24 GMT
Sender: usenet@rice.edu
Organization: Sun-Spots
Lines: 15
Approved: Sun-Spots@rice.edu
Original-Date: Sat, 18 Mar 89 18:49:49 EST
X-Sun-Spots-Digest: Volume 7, Issue 222, message 6 of 13

I see that there are different sets of supported disks under these two
controller types in Sun's 4.0 format.dat file.  The Micropolis 1355 is
listed under the MD21, yet I have a Sun sheobox with a 1355 attached to an
Adaptec.  Is this division as arbitrary as it seems?  I want to take a DEC
rd53 (really a Micropolis 1325), and hang it as the second drive off of
the MD21 in a Sun shoebox that already has a 1355 in it.  I suspect that
this'll work just fine as long as I add an entry for the 1325 off of the
MD21.

I can see that the smaller ribbon from the drive goes directly to the
empty set of pins on the MD21, but do I have to substitute a ribbon with
two connectors for the larger, with both drives chained?  Does adding a
second drive to the MD21 affect performance adversely?  In a previous
incarnation, we attached a Maxtor 1140 to an Adaptec/1325 equipped
shoebox, and it seemed to work fine after we figured out the geometry.