Thought I would share this experience in case others find themselves in the same boat [For the record, my Channels DVR server is a fairly recent Mac Mini M1]...
Over the weekend, I noticed that a show failed to record. Checking the logs, I discovered that Channels DVR could not write to the data disk (an external USB drive). Did some debugging with disk tools and discovered that the drive had become a bit corrupted.
So I grabbed a spare USB HDD, formatted it, and copied everything (did just a drag-and-drop copy) from the corrupted drive to it, making sure to maintain the some directory structure. Fortunately, the copy went cleanly.
I then rebooted into Safe mode and brought up the Disk utility. I renamed the corrupted drive from, eg. "MyDrive" to "MyDrive_old" and renamed the new drive from "NewDrive" to "MyDrive".
After restarting into regular mode, everything is now working just fine without me having to do anything else because the copy of the data on the new drive has the exact same path as before (eg. /Volumes/MyDrive/channels-dvr).
I'd also setup a directory on the external drive as an SMB file share eg. /Volumes/MyDrive/FileShare), as well as a TimeMachine share (eg. /Volumes/MyDrive/TimeMachine). Both of those are also working without me having to do anything else. (I was worried that those would somehow be married to the unique drive ID rather than the mounted file system path)