Issues with AEM Upgrade from 6.2 to 6.3

Hi All,

  we are upgrading our AEM from version 6.2 to 6.3.  we are facing issues when we run pre-upgrade-tasks from the JMX console.

below are the steps we followed and the issues faced.

1. Took the backup of complete instance.

2. downloaded pre-upgrade-tasks-content-cq62-1.2.4.zip package from package share and installed.

3. we ran runAllPreUpgradeTasks() from the JMX Web Console prechecks.

4. when we ran the above we see below information in the logs

        Startup mode is RESTART, nothing to do

        /var/upgrade/status/preUpgradeBackup.force does not exist, backup will not be forced

        UPGRADE NOT NEEDED - StartupMode is RESTART

5. to run the instance in the upgrade mode we restarted the instance with below command

     java -jar -Xmx3072m -Dorg.apache.sling.launchpad.startupmode=update  aem-author-p4502.jar

6. when we restarted the instance in the update runmode and ran runAllPreUpgradeTasks() from the JMX Web Console , we could see in the logs it is preparing for the upgrade with below errors:

    1.  com.day.cq.compat.codeupgrade.impl.mergebackup.CqMergeBackupUpgrade Exception in                                               CqMergeBackupUpgrade.run()     

    javax.jcr.AccessDeniedException: OakAccess0000: Access denied

  2. and we see in the preupgrade popup msg 'disabling replication agents' and the file preUpgradeHCStatus.properties has below content

areAllPreUpgradeHealthChecksOK=false

Maintenance\ Task\ WorkflowPurgeTask=OK

Maintenance\ Task\ RevisionCleanupTask=OK

Modified\ Deprecated\ Indexes=OK

Maintenance\ Task\ com.day.cq.audit.impl.AuditLogMaintenanceTask=OK

Replication\ Agents\ Disabled=HEALTH_CHECK_ERROR

Couldn't figure out the root cause of the issue. Need help and the steps to be followed with upgrade.

Thanks,

Lakshmi.