Dear SCO Customer,

Support Level Supplement (SLS) ptf7074e, the UnixWare 7 st01, sc01 and mc01
Driver Supplement, addresses these issues:

1. Resolves a panic when the tape device is used in variable 
   length block mode.

   The problem was seen to occur with Legato Networker Backup software due 
   to Legato using variable length blocks to a specific tape device. The panic
   could also be reproduced by using tar to one of these tape devices with
   variable blocking enabled.

   The Panther tape library related to this issue is a Robotic tape library
   unit that uses DLT tape units. The actual make was a Storagetek 9710/30 
   with four DLT7000 drives. The drive was connected via a Qlogic HBA.

2. If the tape driver is interrupted then it is possible to be locked 
   out of the tape driver forever (the device is reported as being busy).

   When a command, such as 'cpio -itvI /dev/rmt/ctape1' was aborted by 
   pressing <Del> or <Ctrl>C, the tape device then refused to respond any 
   further with 'device busy' on st01open(). As a temporary workaround,
   'modadmin -U st01' restored the device to normal working operation. 

3. Tape command timeouts were not configurable. Support for the pdi_timeout 
   interface has been added. This is now configurable via the Space.c file.

4. Reading DAT tapes with block sizes other than those with which they 
   were written can lead to incorrect data being returned.

   The problem was originally found when trying to restore data using
   Legato, using 128k blocks. The root issue was found to be related to 
   st01 and the handling of residual data (resulting from the read of 
   only part of a larger tape block). This area of code has been changed 
   to give consistent behavior under such conditions.

5. Removed potential of target drivers causing kma corruption.  st01 (tape)
   sc01 (cdrom) mc01 (medium changer) are all replaced with this SLS. 
   Equivalent fixes for sd01 (disk) will be supplied in ptf7002j (or greater)
   for UnixWare 7.0.0 and in ptf7036e (or greater) for UnixWare 7.0.1.

6. SLS ptf7074 supersedes ptf7059a and therefore incorporates the mc01
   driver fix supplied by ptf7059a. This corrects an error that may be 
   encountered when attempting to load a tape into a DLT library. The 
   error message is similar to: 

      UX: mccntl: ERROR: MC_MOVE_MEDIUM failed on device /dev/mc/mc1
      WARNING: Medium Changer Driver: HA 4 TC 6 LU 0 - CHECK CONDITION
      unix: A "ILLEGAL REQUEST" condition has been detected
      unix: Additional data = "INVALID FIELD IN CDB"

The following issue is new to ptf7074e:

7. tapecntl -c n /dev/rmt/ntape1 (where n is 0 to 3) does not control 
   compression.

SLS ptf7074e contains these files:

        /etc/conf/pack.d/st01/Driver.o
        /etc/conf/pack.d/st01/space.c (updated by postinstall script)
        /etc/conf/pack.d/sc01/Driver.o
        /etc/conf/pack.d/mc01/Driver.o


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

SLS ptf7074e should only be installed on:

       UnixWare 7 Release 7.0.0 with the UnixWare 7 Release Supplement (uw7rs)
       UnixWare 7 Release 7.0.1

SLS ptf7068c (or greater) should be installed prior to installing ptf7074e.

To determine if the SLS ptf7068c (or greater) prerequisite patch is installed,
type the command:

    # pkginfo -l ptf7068 | grep VERSION

If SLS ptf7068c is installed, this command will return "VERSION:  c".

Note: If an earlier version of ptf7068 is installed on the system, then
installation of ptf7074e will fail with this error message:

        UX:pkginstall: ERROR: unknown dependency type specified: S

SLS ptf7074e replaces all versions of SLS ptf7059.  SLS ptf7059 must be
removed prior to installing SLS ptf7074e.


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

1. Download the ptf7074e.Z file to the /tmp directory on your machine.

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

        $ su
        Password: <type your root password>
        # uncompress /tmp/ptf7074e.Z
        # pkgadd -d /tmp/ptf7074e
        # rm /tmp/ptf7074e

3. Reboot the system after installing this SLS package.

The release notes displayed prior to installation can be found in:

        /var/sadm/pkg/ptf7074/install/ptf7074.txt


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

1. As root, remove the SLS package using these commands:

        $ su
        Password: <type your root password>
        # pkgrm ptf7074

2. Reboot the system after removing this SLS package.


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