Re: formating a disk

[p2@porter.asl.dialnet.symbolics.com (Peter Paine)]

    Date: Wed, 26 Jun 91 11:13 PDT
    From: TYSON@ai.sri.com (Mabry Tyson)

	Date: Wed, 26 Jun 91 12:40:52 EST
	From: bouma@cs.purdue.edu

	I had this disk drive that was really messed up after a power outage
	so I did a "disk format" on it.  Now I understand that to get the
	initial FEP filesystem on it I have to do a "disk restore" from the
	IFS tape.  The "disk" commands are in a file "g208-disk.flod".

    I recently had another site ask about a disk problem.  They wanted to format
    the disk too.

    These aren't floppies! [...]

I agree with Mabry. The commands which use words like DISK FORMAT are
perhaps a little misleading when interpreted as one would similar words
appearing when one shoves a new floppy into a Mac.

There are warnings everywhere along the route that allows you to
obliterate your disk (bad block records and all). However, the
references to "Contact your Symbolics support ..." (to which one can
become a bit indifferent) might do with more read ink and reasoning.

That said, I have yet to find an L or G machine disk that would not
succumb to deturmined hacking (hardware failures excepted). It is
possible to get disks up for which IFS tapes and bad block information
has been lost - but what a sweat!

It is very common for people to write over IFS tapes when needing an extra
tape for a backup dump. Similarly, when machines are sold the IFS tape is
often thrown in the trash. This is particularly wasteful as Lisp Machines
have useful lives that span decades (unlike many a fashion box).  If your
disk does not have the bad blocks list printed on it, I'd recommend
sticking a paper list on the drive case for backstop safety.

In parting, the most common source of apparent "bad blocks" that I have
seen is intermittent ethernet connections. You might check out your
etherent cabling before going through the whole palava of giving your
disk month-to-mouth resuscitation.