Dear SCO Customer, The enclosed Support Level Supplement (SLS) UOD393C corrects problems found in the sar utilities and kernel modules. Modifications and new utilities have also been added to assist with performance issues. SLS UOD393C is incompatible with the following SCO software: - The XPG4 EFS - The Local Desktop EFS - The MPX mpsar Supplement In all cases, if any of these packages are installed, remove them before installing SLS UOD393C. After installing SLS UOD393C, do not install any of the packages listed above. Note: If SLS UOD393A, UOD393B, UOD396A or any beta MPX performance or MPX mpsar supplements are installed on the system, please remove them before installing SLS UOD393C. To add another license for SCO MPX 3.0, after installing SLS UOD393C: - Remove this SLS (see instructions below) - Add the additional license - Reinstall this SLS (see instructions below) SLS UOD393C corrects these problems: - Intensive use of pipes and select system calls no longer cause the select system call to hang. - Under heavy use, processes no longer hang on reading from pipes. - The spin loop for exclusive locking of critical kernel code has been increased. This should avoid lock timeout panics on fast systems. - A synchronous write to a file when the file system is full no longer hangs the operating system. - Multiple processors accessing the same static array now all receive correct data. - A panic condition no longer occurs on computers using SCO MPX 3.0, 32MB or greater of memory, and IDE hard drives. - vmstat did not gather reliable MPX information. This utility can now be used to monitor MPX systems and collect reliable system statistics. - sadc now returns memory to the memory pool that it had allocated for its use. - A circumstance where file copies could fail when using SCO MPX has been corrected. - Rapid screen switching between graphical and character screens when using PCI video cards now works correctly. - Accessing QIC tape devices or floppy devices on a system with SLS UOD393A installed could result in a system panic. Performance enhancements: - The system now responds more rapidly to the situation where multiple processes accessed the same file (sleeping on inode access). - The semaphore structure allocation mechanism has been modified to improve performance and avoid data structure corruption. - Calls to the poll routine are handled more efficiently. mpsar/cpusar specific enhancements and corrections: - freemem is now reported more accurately. - runocc/swpocc now reports the run queue occupancy more accurately. - pswtch now looks at the per processor sysinfo. - All processors now update their own syswait structure. - Buffer reads and writes are now reported more accurately. - Sdsk now records the duration of requests properly. - IDA service time statistics are now more accurate. New utilities: - A new sar option to see the number of requests for SCSI request blocks and out of SCSI request blocks has been added. The new option to sar '-S' reports each new counter per second. - The mthread utility was added to report which kernel drivers are multithreaded. Using custom(ADM) to Install or Remove SLS UOD393C A. Installing SLS UOD393C 1. If the system is running in multiuser mode, log in as root on the console. After warning the users that the system will be down for some time, enter the command: shutdown -y -g0 The system will then execute a controlled shutdown operation which displays this message when the shutdown process has completed: ** Safe to Power Off ** -or- ** Press Any Key to Reboot ** 2. Reboot the system. 3. When the system reboots, you will see the message: Type CONTROL-d to proceed with normal startup, (or give root password for System Maintenance): Enter the root password and press . Wait until the "#" prompt appears. 4. Insert the custom volume diskette labeled "UOD393C: MPX 3.0 Performance Supplement 1.0" in the floppy drive and enter the command: /etc/custom The custom menu will appear. 5. To select the following, highlight each one with the cursor keys and press : Install -> A New Product -> Entire Product - Position the cursor so that "Install" is highlighted and press . - Make sure the words "A New Product" are highlighted in the window found in the lower right corner of the screen; press . - Make sure the words "Entire Product" are highlighted in the "Choose an option" section of the screen; press . - You will be prompted to "Insert: Distribution Floppy Volume 1 and press ". The diskette is already in the drive, therefore press . - You will see the following messages: Installing custom data files ... Executing Product Prep Script - You will be prompted to "Insert the requested Volume and press ". The diskette is already in the drive, therefore press . - You will see the message: Extracting Files - When asked if you wish to relink the kernel, reply "y" in order to ensure that the modifications from SLS UOD393C are included in the kernel. Answer "y" when asked if you want to boot off this kernel. Answer "y" when asked if you want to rebuild the kernel environment. - You will then be prompted to "Press any key to continue"; press . - At the main custom menu, move the highlighted entry to "Quit" and press . Press again on the highlighted "yes". - Remove the diskette and reboot the computer. - SLS UOD393C is now successfully installed. B. Removing SLS UOD393C 1. If the system is running in multiuser mode, log in as root on the console. After warning the users that the system will be down for some time, enter the command: shutdown -y -g0 The system will then execute a controlled shutdown operation which displays this message when the shutdown process has completed: ** Safe to Power Off ** -or- ** Press Any Key to Reboot ** 2. Reboot the system. 3. When the system reboots, you will see the message: Type CONTROL-d to proceed with normal startup, (or give root password for System Maintenance): Enter the root password and press . Wait until the "#" prompt appears. 4. Use the custom utility to remove this SLS. At the command line, enter the command: /etc/custom The custom menu will appear. 5. To select the following, highlight each one with the cursor keys and press : Remove -> MPX 3.0 Performance Supplement 1.0 -> ALL - Position the cursor so that "Remove" is highlighted and press . - Make sure to move the highlighted cursor to the package "UOD393C: MPX 3.0 Performance Supplement 1.0" to select this package; press . - Make sure the word "ALL" is highlighted as the selected package to remove; press . - Make sure the word "ALL" is highlighted under "Please verify the removal of the following packages"; press . - When asked if you wish to relink the kernel, reply "y" in order to ensure that the modifications from SLS UOD393C are removed from the kernel. Answer "y" when asked if you want to boot off this kernel. Answer "y" when asked if you want to rebuild the kernel environment. - You will then be prompted to "Press any key to continue"; press . - At the main custom menu, move the highlighted entry to "Quit" and press . Press again on the highlighted "yes". - Reboot the computer. - SLS UOD393C has now been successfully removed. 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