Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ukma!rutgers!cmcl2!ccnysci!alexis
From: alexis@ccnysci.UUCP (Alexis Rosen)
Newsgroups: comp.sys.mac
Subject: Re: Small Problem w/SE30
Message-ID: <1816@ccnysci.UUCP>
Date: 2 May 89 05:33:22 GMT
References: <2473@nmtsun.nmt.edu> <92878@felix.UUCP> <5218@hubcap.clemson.edu> <-539350366@cpl-mfh.UUCP>
Reply-To: alexis@ccnysci.UUCP (Alexis Rosen)
Organization: City College of New York
Lines: 41

In article <-539350366@cpl-mfh.UUCP> martya@cpl-mfh.UUCP (Marty Adelman) writes:
>>><The
>>><new machine has been running flawlessly except that every once in a while
>>><the hard disk turns on when I'm just sitting there doing nothing.  [...]
>
>Since I received quite a few responses from others about this phenomena I
>thought I would post the rather obvious answer about why it was occuring
>in my system.  I fill pretty silly not realising this in the first place.
>
>It was pointed out to me that multifinder will occassionally hcek the 
>desktop to see if any programs have made changes.  Since I rarely used
>multifinder before I purchased the SE/30 I had never noticed the drive
>accesses before. [...]
>
>It was also pointed out to me that if you use a spooler or the disk cache you
>also observe this phenomena, but I don't use either.

This sounds extremely suspect to me. While I am not 100% certain about this,
and would like to hear from someone who is, I am pretty confident...

The Finder does not need to check the desktop. It does something much more
immediate (hooks the file traps or some such, I would guess). If you
create a new file under multifinder, you will notice that the Finder becomes
aware of the new file almost immediately. So I don't think it needs to check
the DeskTop file- which wouldn't store all the information it needs, anyway,
and the file catalog would have to be checked for all open folders, which
would be much too slow.

the disk cache is write-through (almost. this gets messy) so I don't think it
can cause writes at random times. (Clearly reads aren't at isssue.)

The spooler, of course, would cause this behavior.


There are some programs, though, which DO cause this behavior. MacTerminal
is a notable example.

---
Alexis Rosen
alexis@ccnysci.{uucp,bitnet}
alexis@rascal.ics.utexas.edu  (last resort)