I've found the following workaround on the now site (you can adjust size and amount of the debug log files by adding registry entries). I changed it to 10 and that worked. Maybe you can set them off, by setting the DbgLogFile = 0 :
SnapDrive debug log files have filled the local disk
KB ID: 2013953 Version: 1.0 Published date: 12/07/2009
SnapDrive is creating debug log files (Snpdrvdbglog.log) that exceed 20 MB, or an excessive number of debug log files (10 or more) in the SnapDrive program folder on the client's local disk. These accumulate and eventually fill the local disk, causing Windows to shut down.
The size and quantity of the log files that are kept in the SnapDrive program folder is controlled by the following Windows registry entries: [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SWSvc\Parameters]DbgLogSize-dword Maximum log file size in kilobytes DbgLogFiles-dword Maximum number of debug log files
Warning: Editing the registry incorrectly can cause damage to the Windows OS. It is recommended that the registry be backed up before making modifications. For more information consult Microsoft Support.
Add the following registry settings to control the size and number of logs kept on the local drive:
Browse to the registry key: [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SWSvc\Parameters]
Add a new DWORD: DbgLogSize Set the DWORD value to decimal value 00002048. This will set the maximum size of the debug log file to 2048 kilobytes.
Add a new DWORD: DbgLogFiles Set the DWORD value to decimal value 00000010. This will set the maximum number of debug log files to 10.
It is not necessary to restart the Snapdrive service for this to take effect.