Question: Mac cannot stop reading content crazily from a specific drive
My Mac cannot stop reading from a specific external drive crazily (I tried with other drives on this Mac and everything was fine, and I switched to Bootcamp Windows on the same Mac using the same drive, there was no problem). The drive is a RAID0 which is made up of 2 4TB HDDs, connecting to Mac using Thunderbolt. Several days ago (This never happened before), my Mac started to read content from this drive at the speed between 100MB-300MB/s ever since I connect it to Mac. I can see the IO via both Activity Monitor and iStat Menus status bar, but I cannot see which process is doing that, I got no idea how to stop this from happening.
The macOS is the newest non-beta version available. I tried to disable the spotlight indexing service, but it didn't stop. Also, after connecting this drive to my Mac, if I wanna eject it normally without force eject or killing Finder (There was a time I used Terminal to kill Finder, then two Finders appeared in the list. The screenshot is below. Using command+option+esc to relaunch Finder also could not stop reading), I have to shut my Mac down because it is always being used by some crazy program. Firstly I thought it would stop after several minutes then I left it alone. However, after four to five hours, it was still reading, and the Activity Monitor showed that 1.2TB was read by Mac, but it still didn't specify who did that.
While trying to fix the problem, the Bluetooth became unavailable for a time, and the Bluetooth icon in the System Preferences was gone. I restarted for several times but it didn't work, then I left it for several hours and pressed "D" while starting up, the test passed, the Bluetooth became available again. I have so many important files on that external drive, it makes extremely hard for me to access files in it because most of the bandwidth is taken away by that crazy process.
If there's any solution (except for reinstalling macOS), plzzzz tell me. Thank you so much.
MacBook Pro with Retina display, macOS High Sierra (10.13), 15-inch, Mid 2015