This page describes the steps required to revert back to the downlevel system after one or more REM nodes have been upgraded.
Repeat the following steps for every REM host which was either successfully or unsuccessfully upgraded. For hosts where an upgrade was planned but not yet run, no action is required.
Check for a backup
On any host that was (partially) upgraded, there will be a backup. List the backups using the
> ./orca --hosts remhost1 status ... backups = (#2) 20180503-134400 contains REM:184.108.40.206 Plugins:sentinel-gaa-em-220.127.116.11,sentinel-volte-element-manager-18.104.22.168 ...
Look for a backup around the time that the upgrade was carried out (as recorded in the pre-upgrade checklist). If you
find one, progress to the
rollback-rem command below.
If there is no backup with the appropriate timestamp then
orca failed early on in the upgrade process and will not have
made any changes to this host, aside from possibly stopping Tomcat. In this case perform the following steps.
Log into the host and check if Tomcat is running:
ps -ef | grep catalina | grep -v grep
If it is not, start it:
cdto the directory where Tomcat is installed and run
If Tomcat fails to start, refer to the troubleshooting section.
With Tomcat restarted you can move on to the next host to rollback.
After identifying the backup to rollback to, run the
rollback-rem command as follows, replacing
<backup ID> with
the ID of the backup to roll back to (the number preceding it in the status output, without the leading
orca --hosts remhost1 rollback-rem --target <backup ID>
Verify REM services are operating as expected
Follow these steps to verify REM is working as expected.
The rollback procedure for this host is now complete. Move on to the next host to be rolled back.