Does controller translation affect throughput?

[David Schachter]

In article <1990Feb22.070517.837 at llustig.uucp> david at llustig.uucp (David Schachter) writes:
>My system includes a WD1007 disk controller and two drives.  The first drive,
>which has been working well, if slowly, since it was installed, is a Micropolis
>1355.  The system is an Everex Step 386/20, 4MB RAM, running XENIX V R2.3.2.

[The second drive is a Fujitsu MK2244E, 823 cylinders, 5 heads, 35 SPT.]

>
>When I try to copy a lot of stuff to [the 2nd drive] (the news spool area, for
>example,) it churns away for a bit, copying files, and then hangs.  Hangs the
>whole system, in fact.  The drive selected light stays on, I can't login or
>execute any disk-based commands (as opposed to csh builtins) and the system 
>must be reset and rebooted.
>
>Any ideas what is wrong?  I didn't enter the manufacturer's defect list to
>badtrk, as I presumed the WD BIOS surface analysis routine mapped those defects
>out when I entered the list to it.  I.e., I assumed XENIX wouldn't see the
>defects because the defect list no longer corresponded to XENIX's view of the
>disk.
>
>One stupidity up front: I haven't installed xnx133 yet, the WD1007 fix.  I'm
>not entirely sure what it does.  Perhaps if I do, the problem will go away?
>Does anyone know what xnx133 does?

An update: I installed xnx133 and the system no longer hangs!  Now it displays
neatly formatted gibberish.  Well, not really.  It now displays error messages
as described in the (HW) man page for 'hd', while it re-tries over and over.
The system must be rebooted anyway, because neither drive works once the
symptom occurs; attempts to access either drive cause the repeated error
messages.  I've requested WD1007 documentation to figure out what the error
messages mean when they say that commands 20 and 30 failed with status 5110.

I'll reset and reformat the disk for 34 sectors per track, translation to 17,
no sparing, and let XENIX handle the bad tracks, and see what happens.

					-- David Schachter
					   llustig!david at mips.com  OR MAYBE
					   david at llustig.uucp

					   +1 415 328 7425