Last week, I've patch with big success my production Farm (15 servers) and my Disaster recovery Farm (15 servers).
Little explanation about our configuration:
All the db (system, content, search, etc) are located on a SQL Cluster, set with several availability groups. (this point made me having white hairs during the previous Cumulative Updates).
On that Cluster, there is a primary group, where all the changes made in SharePoint (system, content, search, etc...) are committed (Read/Write).
Then, on the secondary group, all dbs are automatically sync from primary to secondary group (thus, in case of ay issue, I can easily have a fresh backup and replace the faulty db).
So, those 2 SQL cluster, are "dedicated" to my Primary Prod SharePoint Farm.
Beside this, I have a backup farm. She is identical to the primary farm, and was designed in case of disaster recovery, to replace the main Farm.
In the procedure, I've changed it to reduce the user impact to it's minimum.
The estimation is 2 time 5 minutes: DNS switch from Primary Farm to Secondary Farm, and Secondary Farm to Primary Farm.
So, to be short, both Farms were patched without issue.
The problem came 3 days later, when the mandatory security patch where applied on half of the servers in the company (Next half is done 2 days later).
I discovered that 1 server was back in "Upgrade required"... Oh, my words!!!!
Then, the day later, I had 5 other servers back in that status.
During that time, we had the support of Microsoft, and they recommend us to execute this powershell command:
Get-SPProduct -local
Reboot the server
Then, I did this procedure, and it works!!!!
After that, I've only execute the powershell command without rebooting the server, and my servers went back to "No Upgrade Required".
This powershell command must be executed on each server that have received a Microsoft security patch.
So, If your farm was successfully patched, and some server are back in the status "Upgrade Required", thus try this powershell command.
Your Farm and server are still up and running, and in take less than 5 minutes to correct the issue.
Voilà,
That’s all Folks !!!
