Dear SCO Customer,

The enclosed Support Level Supplement (SLS) PTF3181, the Dynamic
Loadable Modules Supplement, corrects a problem found with dynamic 
loadable drivers where the reference count is decreased incorrectly 
after multiple concurrent opens. This results in the driver becoming 
unloadable such that 'modadmin -U <drvr>' fails with "Device Busy".

SLS PTF3181 replaces the specfs driver and corrects the reference count
increment/decrement so that drivers can be successfully unloaded after
concurrent opens have occurred.


Software Notes and Recommendations
----------------------------------

SLS PTF3181 can be installed on: 

       SCO UnixWare Application Server Release 2.1.0, 2.1.1, 2.1.2
       SCO UnixWare Personal Edition Release 2.1.0, 2.1.1, 2.1.2


Installation Instructions
-------------------------

1. Download the ptf3181.Z and ptf3181.txt files to the /tmp directory
   on your machine.

2. As root, uncompress the file and add the package to your
   system using these commands:

       $ su
       # uncompress /tmp/ptf3181.Z
       # pkgadd -d /tmp/ptf3181

3. Reboot the system after installing this SLS.


Removal Instructions
---------------------

1. As root, remove the package:

       $ su
       # pkgrm ptf3181

2. Reboot the system after removing this SLS.


If you have questions regarding this SLS, or the product on which it is
installed, please contact your software supplier.

We appreciate your business.

SCO Support Services