Number: 1028

Date:  8-May-84 18':16':09

Submitter: le.pasa

Source: Eric Schoen (Dering.pasa)

Subject: FLOPPY.SCAVENGE and FLOPPY.COMPACT not robust enough -- can munge floppy

Assigned To: 


Status: Open


Problem Type: Bug

Impact: Serious

Difficulty: Hard

Frequency: Intermittent

Priority: Hopefully

System: Operating System

Subsystem: DLion Floppy



Lisp Version: Fugue6

Source Files: 

Microcode Version: 

Memory Size: 

File Server: 

Server Software Version: 

Disposition: [5/9/84 kbr': I''ll see what I can do.  For the time being, it might be a good idea to avoid cramming floppies past 75% full.]

Description: '
 FLOPPY.SCAVENGE and FLOPPY.COMPACT are not robust.  I have had interesting'
experiences with both.  I was unable to fit a file onto a floppy, even though FLOPPY.FREE.PAGES reported I had plenty of space.  I assumed there weren''t enough contiguous blocks available, so I called FLOPPY.COMPACT.  This appeared'
to work fine, as I was able to fit the rest of the files I needed onto floppy. Later, however, I discovered several files were "fractured" on the disk. LAPRD would bail out loading compiled files with bad compiled function errors, '
and it appears that pages of a file were interspersed in pages of other files.'
Later, we ran into problems in which we continually got FILE SYSTEM RESOURCES EXCEEDED breaks (on a different floppy), with Interlisp telling us to scavenge the floppy, as it was "damaged."  Calling FLOPPY.SCAVENGE resulted'
in calls to LISTPUT with a NIL list, which breaks, and several calls to PACKFILENAME with NIL arguments.  If I try to load the resulting floppy into the machine, I get further LISTPUT breaks.  Rescavenging helps, but there are'
several files with names like ?0052 through ?0055, and a bunch of files named NIL.


Test Case: 

Edit-By: Sannella.PA

Edit-Date:  8-May-84 17':35':28