Hey @Alexey 
I had to restart one of my nodes lately because it was failing at browsing a particular folder (cf. Node crashed and restarted after some "error getting current used space", "lstat […] bad message" and "Unrecoverable error").
I scanned its logs in search of such FATAL errors and I could not spot any that would be linked to the normal shutdown of the node. However, there’s still a suspicious ERROR that got triggered both times I had to restart my node gracefully (after the problem in above post got fixed):
[...]
2021-04-01T09:45:10.201Z INFO piecestore uploaded {"Piece ID": "UXPTOJ4TXMW6MO6MW6RSLTTTDI4O2RQRPPD6QRHR5ZNVYWE3373A", "Satellite ID": "121RTSDpyNZVcEU84Ticf2L1ntiuUimbWgfATz21tuvgk3vzoA6", "Action": "PUT", "Size": 512}
2021-04-01T09:45:12.963Z INFO Got a signal from the OS: "terminated"
2021-04-01T09:45:13.151Z ERROR piecestore:cache error getting current used space: {"error": "context canceled; context canceled; context canceled; context canceled; context canceled; context canceled", "errorVerbose": "group:\n--- context canceled\n--- context canceled\n--- context canceled\n--- context canceled\n--- context canceled\n--- context canceled"}
2021-04-01T14:35:21.231Z INFO Configuration loaded {"Location": "/app/config/config.yaml"}
[...]
For your info 