I tried upgrading ambari server from 2.2.2. to 2.6. Backed up the databases as per the instructions too. But scheme upgrade failed and then I am not able to start ambari-server. Please help:
Ambari Server configured for Embedded Postgres. Confirm you have made a backup of the Ambari Server database [y/n] (y)? y INFO: Upgrading database schema INFO: Return code from schema upgrade command, retcode = 1 ERROR: Error executing schema upgrade, please check the server logs. ERROR: Error output from schema upgrade command: ERROR: Exception in thread "main" org.apache.ambari.server.AmbariException: Database version does not meet minimal upgrade requirements. Expected version should be not less than 2.4.0, current version is 2.2.2 at org.apache.ambari.server.upgrade.SchemaUpgradeHelper.main(SchemaUpgradeHelper.java:408) ERROR: Ambari server upgrade failed. Please look at /var/log/ambari-server/ambari-server.log, for more details. ERROR: Exiting with exit code 11. REASON: Schema upgrade failed.
I have faced similar issue recently.
The I upgrade ambari-server 2.2 to 2.4
run ambari-server upgrade
then upgrade it to ambari 2.6.1 and again run ambari-server upgrade.
for ambari agent you can directly upgrade to 2.6.1