Redis QFork.dat Files Taking Up Large Amounts of Disk Space

Symptom

The server hosting the Netwrix Change Tracker web console is running low on disk space. Scanning the server's disks reveals that Redis QFork.dat files are consuming significant storage.

These files are normally stored in the following directory:

C:\Windows\ServiceProfiles\NetworkService\AppData\Local\Redis

Cause

Redis uses the fork UNIX system API to create a point-in-time snapshot of the data store on disk. Windows does not have a fork-like API, so Redis simulates this behavior by placing the Redis heap in a memory mapped file that a child (quasi-forked) process can access. By default, the size of each snapshot file equals the size of the device's physical memory.

Resolution

It is safe to delete these files, as long as the Redis service is not running. Stop the Redis service before deleting the QFork.dat files, then restart the service.