This is due to the files located under C:\Windows\SysWOW64\config\systemprofile\AppData\Local\Redis
Those are used by Redis DB during the CMN Directory Connector run and should have been deleted afterward.
This had been identified as the product defect with defect ID: TF00628849
WORKAROUND:
if those files are filling the drive, then manually delete all RedisQFork_xxxx.dat files from C:\Windows\SysWOW64\config\systemprofile\AppData\Local\Redis
If those files can't be deleted then it's due to be currently used by CMN Directory Connector.
STATUS:
Issue had been resolved in the Coexistence Manager for Notes 3.7.1.30 build and above.
To download latest CMN 3.7.1 hotfix, please click here