🚀 go-pugleaf

Once upon a time I was providing phone support for users of Symbolics'
Lisp Machines.  One day I had a call from one of the users at JPL.  It
seems that they had wanted to allocate a file for a new Lisp image.
(Symbolics machines have two file systems.  The low level FS, called
the FEP file system, consisted of a small number of files with mostly
contiguous disk blocks.  One or two FEP files were used to make the
hierarchical file system, called the Lisp Machine FS or LMFS.  The FEP
FS corresponds loosely to Unix's concept of disk partitions, with the
LMFS being implemented inside the root and /USR partitions.)

Anyway, you might want to create a new FEP file to store a custom Lisp
image or to allocate more space for the LMFS, where most of your data
would live.  The usual way to create such a file was by typing a Lisp
statement like this:

   (with-open-file (a "fep:>file.new" :direction :output)
      (send a :grow 30000))

My JPL customer didn't know this particular incantation.  He *did*
know that the LMFS maintenance tools provided a way to create a new
partition and add it to the LMFS.  So he used these tools to add a new
30,000 block partition to the hierarchical file system.  Then he
stored a Lisp image in the new partition, thereby trashing his entire
file system.  The conversation went something like this:

"You remember the message you received when you selected the LMFS
Maintenance Menu?"

"Yes."

"The one that said that the operations on this menu are extremely
dangerous and can destroy all the data in your file system?"

"Yes."

"Do you remember where it asked if you knew what you were doing and
took full responsibility for your actions?"

"Yes."

"You lied."



-- 
Hank Shiffman                                     (415) 336-4658
Marketing Technical Specialist
Software Engineering Technologies               ...!sun!shiffman
Sun Microsystems, Inc.                          shif...@Sun.com

Zippy sez:
  Well, I'm INVISIBLE AGAIN..  I might as well pay a visit to the
 LADIES ROOM...