Linux tips
check if ports are open
nc -vz <host> <port>
see cpu frequencies
lscpu --all --extended
get more disk space by limiting reserved space for root
tune2fs -m0 /dev/<disk>
get disk space information
du -sh /home/polkadot/*
df -h
rotatekeys
curl -H "Content-Type: application/json" -d '{"id":1, "jsonrpc":"2.0", "method": "author_rotateKeys", "params":[]}' http://localhost:9900 > session.key
check session keys
curl -H "Content-Type: application/json" -d '{"id":1, "jsonrpc":"2.0", "method": "author_hasSessionKeys", "params":["<session key 0x.....>"]}' http://localhost:<rpc port>