bitcoind starting and then quickly shutting down automatically Lenovo E460, 8GB RAM,
Fedora 26,
bitcoin core command line version 0.16.0,
All blocks completely downloaded on a flash drive with 256GB capacity.

I rebooted my machine today without stopping the bitcoind before and since then the following happens:
1) starting "bitcoind -daemon -datadir=/path/to/flash/drive"
2) I see with "top" the process 'bitcoind'  running  for about 30-45 seconds
3) Suddenly under same process id the process names changes to "bitcoin-shutdown" and disappears a second after.
4) Stop or new start of bitcoind is not possible, message is "Error: Cannot obtain a lock on data directory /path/to/flash/drive. Bitcoin Core is probably already running." 
5) Only way to start bitcoind again is to reboot the linux. Then loop 1)-5) starts again.

Any help appreciated!
Thanks!
The solution is time consuming but easy. The flash drive was finally reporting read/write errors after a harsh shutdown. Formatting it and new install of bitcoind and loading all blocks again (I had no other drive where I could have copied this amount of data to and wanted to exclude potential issues with the old file permissions).

So the next few days I assume the machine will be busy. However now at block 8000 the CPU is only using 1-2% (Intel Core i5 with 8GB RAM on fedora linux)