Fatal Disk Error urgency [1]

[Reti@STONY-BROOK.SCRC.Symbolics.COM (Kalman Reti)]

    Date: Wed, 18 Jul 90 08:24 PDT
    From: Chucko@CHARON.arc.nasa.gov (Charles R. Fry)

	Date: Tue, 17 Jul 90 23:44 EDT
	From: Reti@WESER.sreti.symbolics.com (Kalman Reti)

	    Date: Tue, 12 Jun 90 10:08-0000
	    From: p2@Porter.ASL.dialnet.symbolics.com (Peter Paine)

	    What can one do with the FSMAINT [Active Structure Edit] LMFS interface?

	Lots.  Mostly you can look at the record buffers of files while they are in use
	by LMFS.  Since these change frequently, what you see on the screen is only an
	instantaneous snapshot of what's going on unless you are holding the LMFS lock.
	It also allows you to change things in those data structures (using LMFS::DDT),
	but I'd advise against that 1unless you really know what you are doing.

0    OK, I'll bite.  How does one learn enough to know how to use this??  
You can use the tool as a read-only one without any particular harm; it will actually
teach you some of what you need to know.  I was only referring to the ability to
change the active structures while LMFS was up in my warning.  I think
it is probably a bad idea to use active structure edit to actually modify the data structures 2in
situ0; I've been reading LMFS code for years and frequently deal with broken
file systems, and prefer to do my fixing up on disk instead of in virtual memory.
You have a lot more time to remember something you've forgotten and fix it before
it causes irreparable damage.
									 I
    feel Symbolics should provide a document in some form that describes
    these data structures, though not necessarily as part of the online
    docs.  The sources are NOT adequate when you're in a hurry to repair
    some file system damage.
I guess I always found the sources adequate, since that was exactly the situation
when I first got into the LMFS-fixing business.

     -- Chuck Fry  Chucko@Charon.ARC.NASA.GOV
	Information Sciences Systems Group
	NASA Ames Research Center