[comp.sys.mac] What to do when your HD disappears

hammen@csd4.milw.wisc.edu (Robert Joseph Hammen) (11/23/87)

Recently, several people have been posting messages about their Mac II hard
drives "disappearing" after a crash or reboot. Here are some things to try to
recover your hard disk:

1) Boot the Macintosh II from a System Tools floppy. Hold down the Command,
Option, and Shift (and possibly Control?) keys while pulling down the Control
Panel DA. You will get a message saying something like "Are you sure you want
to zap PRAM?". Select yes. Then, attempt to reboot. 

2) Boot with a utilities floppy. Run the HD SC Setup application (1.5 is the
latest and most preferable) and re-install the SCSI driver on your hard disk.
(do this with the "Update" function). Again, attempt to reboot.

3) Boot with the Utilities disk. Select the "Disk First Aid" application and
use the "Set Startup" option in the Special menu of the Finder to make it
the startup application. Reboot, and you should be in Disk First Aid. Open 
the hard disk volume, if you can. Before you click on "Start" to begin
scavenging the disk, you might want to type Command-S - this will give you a
more detailed explanation of what the program is doing. After DFA does its 
bit, you might wish to try to reboot again.

Note that if the hard disk does show up in the Finder, and will not boot,
despite any attempts to make it the "Startup Device" in the Control Panel,
you might want to try throwing away the System file and replacing it with a
virgin one.

If you can't get the hard disk to mount, try to find a copy of Paul Mercer's
SCSI Tools cdev (control panel file). It will scan the SCSI Bus for devices
and will attempt to mount them.

If you still can't recover the hard drive, consider purchasing MacZap. The
MacZap Recover HFS application is good at recovering trashed disks that other
programs can't touch. I got my copy for ~$35 from ComputerWare.


=========================================================================
Robert Hammen	Computer Applications, Inc.	hammen@csd4.milw.wisc.edu
Delphi: HAMMEN		GEnie: R.Hammen		CI$: 70701,2104

creech@unc.cs.unc.edu (Jeff Creech) (11/24/87)

In article <3611@uwmcsd1.UUCP> hammen@csd4.milw.wisc.edu.UUCP (Robert Hammen) writes:
>Recently, several people have been posting messages about their Mac II hard
>drives "disappearing" after a crash or reboot. Here are some things to try to
>recover your hard disk:
>
>1) Boot the Macintosh II from a System Tools floppy. Hold down the Command,

I really appreciate all the replies of "you're doing the right thing
just use the system tools disk to reinstall the SCSI driver."

I want to *why* it is that some of the Mac II's are losing their SCSI drivers
several times a week.  This not what we are paid five grand for!

Does Apple have an *answer* to this problem?

This is really getting annoying. (nothing personal Robert.)

Jeff Creech
Macintosh Systems Specialist
Computer Services
UNC-CH Dept. of Computer Science

tecot@apple.UUCP (Ed Tecot) (11/30/87)

In article <2167@unc.cs.unc.edu> creech@unc.UUCP (Jeff Creech) writes:
>I want to *why* it is that some of the Mac II's are losing their SCSI drivers
>several times a week.  This not what we are paid five grand for!
>
>Does Apple have an *answer* to this problem?

Here is my assessment:
When an application crashes, it may end up executing random memory.  We have
determined that a particular trap, SetOSDefault, has a high probability of
being executed when an application goes astray.  This trap will cause your
startup disk to attempt to boot from a different (nonexeistent) partition.
The fix is to reset your parameter RAM, as far as I know, the SCSI driver
is not touched.  We have a fix for this problem (although it would be nice
if applications didn't have these bugs).

To determine if you are hitting this, the next time your hard disk refuses
to boot, boot off of a floppy, and open the control panel with
command-option-shift depressed to reset the parameter RAM.  Then attempt to
reboot.  If this fails, tell me.  If this succeeds, post the programs,
DAs, INITs, etc. that you use, so that we have some hope of finding the
culprit.

						_emt