Linux tips
Example ports and hosts used, change to your own setup.
check if ports are open
nc -vz 1.2.3.4 30333
see cpu frequencies
lscpu --all --extended
get more disk space by limiting reserved space for root
Default is 5% which is 50GB on a 1000 GB system, 0.1 (1GB) is more suitable.
tune2fs -m0.1 /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:9944 > 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:9944
see number of processes at a certain port
netstat -tn src :30333 | wc -l
convert raid1 to raid0
Sometimes you want to combine two raid disk to one, gaining space but sacrificing redundancy. Only do this with non vital data. See also https://zedt.eu/tech/linux/how-to-convert-mdadm-raid1-array-to-raid0/. After the --level=0
command raid will switch to raid 4 and after rebuilding to raid 0. Sometimes you have two wait between command for the rebuild to finish.
mdadm --detail /dev/md1
mdadm /dev/md1 --grow --level=0
mdadm /dev/md1 --grow --raid-devices=2 --add /dev/sdb1
fdisk /dev/md1
growpart /dev/md1 1
resize2fs /dev/md1p1