Dear SCO Customer, Support Level Supplement (SLS) OSS485A, the Memory Supplement, corrects problems in parts of the system which place an excessive demand on low memory (memory with an address under 16Mb). See the list below for more details on specific problems addressed by this SLS. RELEASE INFORMATION SLS OSS485A is intended for use on these products: SCO OpenServer Enterprise System Release 5.0.4 SCO OpenServer Desktop System Release 5.0.4 SCO OpenServer Host System Release 5.0.4 The following supplement MUST be installed prior to installing SLS OSS485A: SCO OpenServer Release Supplement 5.0.4c (rs504c) ftp://ftp.sco.com/Supplements/rs504c/ SLS OSS485A corrects the problems listed below. In each case, the symptoms are the same: the system performance severely degrades and the vhand process is seen, with ps(C) ("ps -p2"), to be using all or most of CPU time. The cause is that vhand is looking for low memory which is not available. 1. The High Performance Pipe System was incorrectly allocating low memory. The solution is to allocate non-low memory. 2. Terminal opens were incorrectly allocating low memory. 3. The kernel memory allocator was too readily handing out low memory. 4. The streams buffer allocator was too readily handing out low memory. I. INSTALLING SLS OSS485A 1. Prepare the media for installation. Download the OSS485A media image file (oss485a file), place the file in the /tmp directory, and rename the file by typing the following command: mv /tmp/oss485a /tmp/VOL.000.000 2. Run the Software Manager with the command: # scoadmin software or double-click on the Software Manager icon in the desktop. 3. Pull down the "Software" menu and select "Install New". 4. When prompted for the host to install from, choose the local machine and then "Continue". 5. When prompted to select the media device: If you are installing this SLS from diskette media, select the appropriate floppy disk drive and then "Continue". Proceed to step 6. If you are installing this SLS from media images per step 1, select "Media Images", then "Continue". When prompted for the "Image Directory", enter "/tmp" (or the directory where you placed the VOL file in step 1) and then select "OK". 6. When prompted to select software to install, ensure that the "OSS485A" entry is highlighted. Choose "Install". 7. You will be asked whether or not you want to relink the kernel. Enter "y" or "n" based on this message. Note that you will not be able to make use of the patch until you relink the kernel. Therefore, it is suggested that you answer "y" to this question. 8. Once the installation finishes, quit the Software Manager. Installation of SLS OSS485A is now complete. The changes will take effect the next time you reboot the system. 9. Log in as root on tty01 and shut down the system: # shutdown -g0 -y After shutting down and rebooting the machine, application of SLS OSS485A is complete. II. REMOVING SLS OSS485A Note: Patches must be rolled back in the reverse order in which they were installed on a per-component basis. 1. Log in as root. 2. Execute the command: # scoadmin software or double-click on the Software Manager icon in the desktop. 3. Highlight "OSS485A: OpenServer Memory Supplement." 4. Pull down the "Software" menu and select "Remove Software". NOTE: There may be "Verification Errors" at this stage because the file .../io.a has an incorrect checksum. This warning can safely be ignored. 5. You will be asked whether or not you want to relink the kernel. Enter "y" or "n" based on this message. Note that package removal will not take effect until you relink the kernel. Therefore, it is suggested that you answer "y" to this question. 6. Once the removal finishes, quit the Software Manager. 7. As root on tty01, shut down the system: # shutdown -g0 -y After shutting down and rebooting the machine, removal of this SLS is complete. 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