Potential data loss warning in RetentionAgent: %1
This message will indicate which diagnostic log is reaching the maximum size limit. Example:
The size of this folder C:\Program Files\Microsoft\Exchange Server\V15\Logging\Diagnostics\DailyPerformanceLogs has reached 95% of max size allowed - 5120 MB. Some data will be purged once it reaches the max limit.
You can edit the maximum size limit for each diagnostic log in the Microsoft.Exchange.Diagnostics.Service.exe.config file. This file is usually located in C:\Program Files\Microsoft\Exchange Server\V##\bin\ (where ## is your exchange version, such as 15) and to edit the size limit for the file listed in the example, you would change the MaxSize value in this line: