Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!ric
From: ric@Apple.COM (Ric Urrutia)
Newsgroups: comp.unix.aux
Subject: Re: mkfs and 80SC interleaving
Message-ID: <31055@apple.Apple.COM>
Date: 18 May 89 21:35:07 GMT
References: <42900002@m.cs.uiuc.edu>
Organization: Apple Computer Inc, Cupertino, CA
Lines: 24

In article <42900002@m.cs.uiuc.edu> coolidge@m.cs.uiuc.edu writes:
>
>We've got several Apple 80SC's (external and internal) used for A/UX
>in our lab. Recently we set up one of the Macs as an NFS server for
>the rest of them and reformatted a previously MacOS drive as a second
>A/UX drive. The new drive's performance seems to be really bad, and it
>seems to be doing far too much seeking. I suspect that by using the m
>and n (interleaving) parameters with mkfs the performance could be
>greatly improved.
>
>Does anyone know the "right" interleaving numbers for an internal (or,
>for that matter, an external) 80SC, especially one used mostly as
>an NFS-mounted server drive?



The mkfs program defaults to an interleave of 7:400.  Reconstruct your
free list by issuing the command: fsck -s500:1 and your access time
will increase dramatically.  I ran some benchmarks on my macII and found
the writes to be about 8 times faster and the reads about 3 times faster.

By the way, the root partition comes delivered with the interleave factor
properly set up.  It's just additional partitions which must be created
with "mkfs /dev/dsk/c?d?s? ??000 1:500".