where can I see chain-id after I've run "witness_node"

[pc]

The chain ID is basically a hash of the genesis file. Depending on your logging configuration it should end up in the logs as well as on the console.

[Kati]

It's printed into a console. Is there other place where I can see chain-id later, after I disconnect from my server? Somewhere in logs or config?

It's private network, testnet