Buying UNIX for a clone

[Bill Heiser]

In article <1991May01.172734.10760 at nstar.rn.com> larry at nstar.rn.com (Larry Snyder) writes:
>bill at unixland.uucp (Bill Heiser) writes:
>
>>the bus and build up a daisy chain of drives.  As it turns out, with 
>>one combination of drives I just happen to have, I can't run SCSICNTL
>>or debug on one of the drives!  To do so, I need to disconnect one of
>>the drives.  This is just one example of subtle little incompatibilities.
>
>what drive gives you the problems with scsicntl?

I have the following configuration.  The bus is terminated correctly 
(at each end), and all drives/host adapter are configured for parity.
I experimented with various methods of providing scsi terminating power,
to no avail.

   CDC Wren IV
   SCSI ID 1 --|
               |
   Archive     |
   Viper 2150S |
   SCSI ID 4 --|       When running SCSICNTL in this configuration,
               |       it reports something like "drive did not respond
   Adaptec     |       to drive size query" (or something along those
   1542b HA    |       lines).  The Toshiba drive info doesn't show up
   SCSI ID 7 --|       in the "select unit" menu.  When running with
               |       either the Toshiba or Maxtor disconnected, and
               |       terminations/scsi ids changed as appropriate,
   Toshiba     |       everything is fine.
   MK-156FB    |
   SCSI ID 2 --|       This configuration has been running with Esix for
               |       several weeks now.  The only anomaly I've noticed
   Maxtor      |       so far (aside from not being able to properly use
   8760S       |       SCSICNTL or DEBUG) is that my UUCP *INBOUND* rates
   SCSI ID 0 --|       have fallen from 1250 CPS to 700 CPS !!!  VERY ODD!


To answer your question, I'm not sure which drive causes the problem.  It
seems to be some incompatibility problem between the Toshiba and Maxtor
drives.  Someone suggested that these two drives don't implement SCSI
protocol very well, so they wouldn't be happy co-existing.

-- 
bill at unixland.uucp                 The Think_Tank BBS & Public Access Unix
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