Installation Order Summary for SCO, SMP, Patches, EFS, and Agents:
The SCO operating system is particular about the order software is installed and removed. A SCO 5.0.5 or 5.0.4 system should have its software installed in the following order:
To maintain this order while upgrading SCO Patches or the Compaq EFS, one should remove off the outer layers until you reach the appropriate point where you should install your new software (SCO Patches and/or Compaq EFS).
Applying Compaq EFS and SCO 5.0.5 or 5.0.4 Patches:
Start with a good backup. Make sure your backup will work if you need it.
Make sure your boot and root disks are functional and give you access to your hard drives, tape backup, and the network (if needed to access your backup).
Gather network settings. Some information can be gathered by
ifconfig -a >/tmp/ifconfig.out; netstat -r >/tmp/netstatr.out; netstat -rn >/tmp/netstatrn.out
Also be sure to look in "netconfig" to gather other settings.
Reboot to single user mode
Verify that you are in single user maintenance mode by running the "who -r" command. On the line returned from "who -r" you should see a piece that says "run-level S" which menas single user mode. If "who -r" returns any other value, then you need to try again until you properly enter single user maintenance mode.
Run "netconfig"
Remove all compaq NIC's (Remember to write down the network settings before you remove them)
Run "custom"
Remove the Compaq Insight Agents
Remove the Compaq EFS
If necessary, remove the SCO patches (preferrably in the opposite order installed)
Install SCO SMP (for multiprocessing) if needed (SCO SMP must be installed before any SCO patches)
One additional patch for SCO 5.0.4 that is not mentioned on SCO's minimum patch listing page is oss496a, the RTC (Real Time Clock) Patch. This patch for SCO 5.0.4 addresses NVRAM corruption, 212 Processor Failure, and time drift throughout the day. This issue is present in SCO 5.0.5, but is taken care of by rs505a. If your system (SCO 5.0.5 or 5.0.4) has been running without this patch, it may be a good idea to patch the system first according to the steps listed above, then clear NVRAM through advanced mode of SCU.