(so I yanked it out and re-connected and then it became visible again)
Not sure how to proceed…
First step should be: replace the USB Cable and/or USB port. If it happened once, it may happen again.
Frequent unexpected removal of your external drive could cause data corruption at some point.
(
LoyceV beat me to it, about the cable)
Or could it be that I can pick up the dl where it left off?
It will, but if there's a corruption, Bitcoin Core will detect it and will suggest you to reindex.
It's a good thing that your blockchain isn't "
pruned":
2024-08-18T19:02:25Z Setting NODE_NETWORK on non-prune mode
Otherwise, a corrupted chainstate or block will require you to start from scratch.