So I was doing all this because I want to monitor some stats from my NAS through SSH as described in this post by @EventuallyFixed . That means a one line login, no password. I finally got it working with this line…
ssh -o PubkeyAcceptedKeyTypes=ssh-rsa -i <link to private key> -o KexAlgorithms=+diffie-hellman-group1-sha1 -o HostKeyAlgorithms=+ssh-rsa root@host
Then I just needed this line to grab the data…
df /dev/md2 | awk 'FNR == 2 {print $5}'
I’m so happy it’s working. My NAS is an ancient (at least 10 years old) WD My Book World Edition. No integration, no SNMP. So as far as I know, this is the only option. Thanks to @heckler & @EventuallyFixed for the help!