Patching SharePoint 2016

Pre-Reqs:

1. SharePoint Shell Access permissions on the Farm and Admin databases, as well as any Web Applications databases.
2. Farm Administrators within SharePoint Central Administration.
3. Local administrator on all the SharePoint Farm servers.

Install the SharePoint Cumulative Update on all SharePoint servers in your farm. Then run the below command on the Central Admin server first, then your application servers then the Web Front Ends last.

Command:

Run the command in SharePoint Powershell:
psconfig.exe -cmd -upgrade -inplace b2b -wait -cmd applicationcontent -install -cmd installfeatures -cmd secureresources

Note – if you have 1 unsuccessful configuration, sometime i find if you run it a second time it will work. This could be because there is a lock on the database or CA.

Rollback:

The only rollback method for patching SharePoint is restoring all the virtual machines in the farm including the Distributed Cache and Web Front Ends, as well as all SharePoint related databases.

You cant go to Installed Updates and try to uninstall it from there as you it wont allow you to uninstall.

You will find a tonne of issues if you only restore the databases. I know as this happened to me and it was near impossible to resolve.

Note, this is unsupported via Microsoft so only do it as a last resort.