Dear Andrea-
I believe that this is a limitation of DOS and applies to all disks,
hard, floppy, or otherwise.  It's hard to believe that the problem has
persisted through so many generations of DOS.  Which version of DOS do
you have?
 
Tony Moss
Auburn University
 
 
On Fri, 3 Feb 1995, Andrea Elberger wrote:
 
> We want to pass along this warning to anyone using optical disks:
>
>         We are a multi-user facility with a Bio-Rad MRC-1000.  We have
> Panasonic 1 gigabyte read/write/erasable optical disks as our mass storage
> medium.  One of our users has had a persistent problem which was unique but
> happened to every new disk we gave her lab within a 2-3 week period.  After
> tearing our hair out, working with Bio-Rad technical support and service
> person, a casual conversation with a computer expert solved the problem.  It
> seems that this user was collecting single optical slice files (relatively
> small number of bytes) therefore she was able to accumulate 300, 500 or similar
> ranges on each side of the disk.  Evidently, there is some limit to the ability
> of the root directory to store a given number of files. My computer expert
> recommended that several subdirectories be made, and those do not suffer from
> the same problem.  We then limit the number of files in the root directory to
> about 100, set up subdirectories that can have several hundred files, and then
> the problem disappears.  The user can now write to her disk all the time, and
> no files have been scrambled.  I am not sure if this applies to all optical
> disks, but if anyone out there has had problems where disks containing several
> hundred files can be read but not written to, this may be your solution.
>
>         Dr. Andrea Elberger
>         Professor, Anatomy and Neurobiology
>         The University of Tennessee, Memphis
>         [log in to unmask]
>