Was running portal for arcgis 10.4.1 on windows 2008 r2 standard with high availability. Upgrading to version 10.6.1 as follows
1 Run 10.6.1 install on standby machine and successfully authorised license
2 Run 10.6.1 install in the primary machine and authorised licence
3 After clicking "Continue Portal Upgrade" but the process fails after running for some time with the following error "Upgrade failed. Index Service configuration failed."
Any ideas I can get round this problem?
You could take a look at the logs under C:\Program Files\ArcGIS\Portal\framework\runtime\ds\usr\logs\<machine>\elasticlog to see what's going on. My assumption is the index service can't start correctly. You can post any errors here if you'd like, or reach out to Support for further troubleshooting.