Our server was accidentally upgraded; can it be downgraded?

[admin admin]

My server is reporting;
Database build number: 800009
JIRA app build number: 712004

The installer was accidentally run on the live system (v7.12.3) for v8.0.1.  And while the installation was cancelled, and the server remaind opreable, it altered the numbers above such that when the system was powered off, the mistake became apparent as the server will not start again with the v7.12.3, nor the v8.0.1.

I want to revert the server to the previous version (7.12.3), and experienced help would be well welcomed.

[admin admin · Accepted solution]

Adding this line to the ${JIRA_INSTALL}/bin/setenv.sh file provided what I required, as below;

JVM_SUPPORT_RECOMMENDED_ARGS="-Djira.downgrade.allowed=true"

[Joe Pitt]

Unless the v8.0.1 instructions have a different backout option, you'll need to restore the backup you hopefully have from your normal maintenance schedule. If the v7.12.3 won't start I believe you'll need uninstall JIRA and install a fresh copy of v7.12.3 and restore from the backup.