Cannot turn System 7 File Sharing On
L. Weissman
September 4, 1996

Lately we have encountered several cases of Mac (mainly PCI) not completing the Sharing startup successfuly.
This for example may cause the Mac to be unaccessible on the SCINET.

The below note gives some hints on how to overcome the problem.

DOS volumes mounted with PC Exchange.

Look for adequate space on the volumes being shared on your
computer. System 7.x creates a few support files for file
sharing, and if there is insufficient space on ANY attached
disk or partition, file sharing is not enabled. File sharing
requires at least 360K of disk space available on each
connected disk or partition. More space may be required when
there are many Users and Groups. If any volume has less than
360K available, File Sharing reports "File Sharing Cannot Be
Enabled."

The only exception to this requirement concerns locked volumes,
like CD-ROMs. The information required for sharing a locked
volume is stored on the startup disk instead.

Adequate RAM

File sharing requires about 268K of RAM (Random Access Memory)
to operate. Applications may not launch, if your Macintosh has
less memory than the application requires. Either remove
unnecessary extensions to a folder outside the System Folder,
or acquire additional RAM for your computer.

Reset Parameter RAM

Zap (reset) the PRAM (Parameter RAM) by pressing the key
sequence Command-Option-P-R while starting your System
7.x-equipped computer. This resets the serial ports, so you may
need to reactivate AppleTalk on some Macintosh computers.

Conflicting Extensions

Check for conflicting extensions by using the Extensions
Manager control panel to turn off all extensions that do not
come with system software. Restart, if file sharing now works,
find the conflicting extension by turning the extensions on one
at a time.

Delete Users & Groups Data File

If you are sharing only the startup volume, and the startup
volume is the only volume attached to the computer, try the
following steps. However, if you have more than one volume,
skip this section.

Step 1
Turn file sharing off using the Sharing Setup control panel.

Step 2
Move (do not delete) the Users & Groups data file, in the
Preferences folder, to another folder outside the System
folder.

Step 3
Restart the computer.

Step 4
Open the Sharing Setup control panel, and enter a new Owner
Name, Owner Password, and Macintosh Name, replacing any
previous data. Be sure to use new or different names.

Step 5
Turn File Sharing on.

If this does not resolve the problem, move the Users & Groups
data file back into the Preferences folder.

Delete the File Sharing Folder

Step 1
Delete the File Sharing folder from the Preferences folder
within the System Folder.

Step 2
Restart the computer.

Step 3
Turn File Sharing on.

Third-Party Formatting Software

If you format any media with a third-party utility, check with
the vendor for compatibility with File Sharing and replace the
driver if necessary.

Recreate the AppleShare PDS File

You can delete an invisible file called AppleShare PDS on the
top level of all connected volumes when sharing. The AppleShare
PDS file may need to be deleted on each volume on multiple
drive systems, or drives with multiple partitions.

To help troubleshoot in multiple drive situations, start the
computer with just the startup volume on. If file sharing works
in this configuration, add another drive to the chain and test
file sharing each time until you find the drive that prevents
file sharing from starting. You can then concentrate on the
drive that fails and remove its PDS file.

IMPORTANT: Deleting the PDS file removes all access privileges
assigned to folders. You need to reassign access privileges to
the folders.

Step 1
Delete the PDS file with ResEdit or a third-party utility that
lets you view invisible files. Use the utility to unlock the
file and make it visible on the desktop so you can drag it to
the Trash.

If you do not have a utility, try to replace the Owner Name and
Macintosh Name in the Sharing Setup control panel with
different text. You can change them back to their original
values later. When you start File Sharing, the system creates a
new AppleShare PDS file on the startup volume.

Step 2
Restart the computer.

Step 3
Turn File Sharing on. New AppleShare PDS files are created.

Re-install Software

Before reformatting the hard disk, try re-installing the system
software or File-Sharing software and restart the computer.

Reformat

Back up the data and reformat the media. A bad block may be
causing the problem.

IMPORTANT: Be sure to back up your data before reformatting.
The formatting process erases all data from the volume.