System Update hangs at 30-40% on ZENworks 11.2 Appliance

The system update being applied is baselined in the zone
The system update started automatically immediately after being added to the zone
The appliance was rebooted before the update completed

The following or similar errors are seen in the system-update.log:

DEBUG;;;Launching rpm command with parameter: [/bin/rpm  -e  --verbose  --nodeps  novell-zenworks-zencore-agent]
DEBUG;;;return code : 1
DEBUG;;;Checking if any version of the rpm 'novell-zenworks-zencore-agent' has been installed.
DEBUG;;;Executing query: [/bin/rpm, -q, novell-zenworks-zencore-agent, --queryformat, @%{version}.%{release}@]
DEBUG;;;FailureRPM Query failed with return code: 1

DEBUG;;;Checking if any version of the rpm 'novell-zenworks-zesm-langs-server' has been installed.
DEBUG;;;Executing query: [/bin/rpm, -q, novell-zenworks-zesm-langs-server, --queryformat, @%{version}.%{release}@]
DEBUG;;;Verifying if SELinux is installed.
DEBUG;;;return code : 143

ERROR;RPM_INSTALL_ERROR;[/bin/rpm  -e  --verbose  --nodeps  novell-zenworks-zesm-server],255;null
DEBUG;;;An error occured during command execution...details should have already been logged

1. Verify that there are multiple instances of zenupdater running with the following command:
   ps aux | grep zenupdater | grep -v grep
2. If there are multiple instances running, kill them with this command:
   ps aux | grep zenupdater | grep -v grep | awk '{print $2}' | xargs kill -9
3. Delete the baselined update from ZCC > Configuration > System Updates
4. Re-import the update and deploy it to the appliance
   

There were multiple instances of zenupdater running at once. The rpm installs were locking each other out.

For a similar issue that can occur during a migration from the ZENworks 11.2 appliance to the ZENworks 11.3 appliance, please refer to TID 7014987.