Microsoft have done a good job making the patching process for Skype for Business as simple as possible but over time it is possible that you may suddenly come across a server that will just not install a CU.
When you look at the logs the error doesn’t give you a lot of information to work on:
Executing command: msiexec.exe /update “Server.msp” /passive /norestart /l*vx “c:patchesServer.msp-SRV01-[2018-11-28][19-27-42]_log.txt”
ERROR 1603: Server.msp had errors installing.
ERROR: SkypeServerUpdateInstaller failed to successfully install all patches
Luckily if does give you a log file in the first line. A REALLY BIG log file.
If you search for “error” then you will likely find a few but don’t get too worried. In particular one entry points you yet another log. This is located in the AppData\Local\Temp folder of the user running the upgrade and is called LCSSetup_Commands.txt. Inside this you will find the following information:
Install-CsDatabase : Command execution failed: Install-CsDatabase was unable to find suitable drives for storing the database files. This is often due to insufficient disk space; typically you should have at least 32 GB of free space before attempting to create databases. However, there are other possible reasons why this command could have failed. For more information, see http://ift.tt/1Og9jlm
So it seems that Skype for Business won’t patch the database if the disk on the server drops below a certain threshold. This log mentions 32GB but we’ve found that it will go lower than this.
After a bit of housekeeping the patch will run through successfully.