Flash drive failure

The USB drive I was booting my pi from is failing - it will not boot now and I can only access the files on it from my Linux “tinkering” laptop. When I plug it into my main windows machine it beeps like it’s being rapidly plugged and unplugged.

Is it possible to make a backup manually? What files do I need to copy off of the drive?

Basically you need the content of the /var/lib/openhab directory and its sub directories.
There are a few exceptions (backups, cache, tmp ) which are not needed.
On top you need the content of /etc/openhab.
Depending on which external ( not rrd4j, mapdb, db4o ) persistence service or external service ( like mosquitto broker ) you configured that also need to be taken into account.

Windows does not know this filesystem so windows can’t read it.

Oh I completely understand that windows would not recognize the file system - I was just seeing if windows would recognize the drive as existing. It did not. Thankfully my Linux box did (even if it was moving at about USB 1 speed) and I got the drive imaged and I will attempt to pull the files this evening when I get off work. Then I have to find a decent drive to replace it. And properly make a backup this time.