Can't clear database (delete all data)

I have 3 server clusters for the test environment, I want to clear/delete every data in this cluster. I tried

fdbcli> clearrange "" \xff

but it’s not working still data remains in the cluster. with this command, I managed to delete 4.5GB of a total of 9.6GB total disk space used. The deletion process was going very slowly it took about 4 hours to delete this much I don’t think that is normal, and now it stopped progressing. I don’t know what to do and there is not much on the internet about this topic. if you guys could help I appreciate it a lot. here is my configuration below:

The reason for slow deletion process is that the clear operation itself writes a tome stone to the database, which is very quick. However, the actual deletion of data happens in the background, and is slow, because the background deletion should minimally affect the regular client transaction traffic.

The particular reason is that the default SQLite storage engine is B-tree, and clearing the whole database means all existing SQLite pages need to be removed, which is inefficient.