Exchange 2013 MSDiagnostics Error 1006

Error exist from exchange 2013 RTM to 2013 CU3
Error look like:

The performance counter ‘\\SERVER\LogicalDisk(HarddiskVolume1)\Free Megabytes’ sustained a value of ’0,15′, for the ’10′ minute(s) interval starting at ’8/20/2013 7:21:00 AM’. Additional information: None. Trigger Name:DatabaseDriveSpaceTrigger. Instance:exchndb1

It is not clear what does this error means, because 50% of hard drive space is free.
You can disable this notification. To do this edit configuration file:

C:\Program Files\Microsoft\ExchangeServer\V15\Bin\Microsoft.Exchange.Diagnostics.Service.exe.config

Change “ExchangeJobs.Triggers.DatabaseDriveSpaceTrigger” from “True” to “False”. After making changes do not forget to restart exchange diagnostic service.