Hello, this is a weird one and the first time ever I see this in my life but after a power failure, my F39 server doesn’t allow anyone to login locally or from ssh. This is what I get in ssh,
debug3: send packet: type 50
debug3: receive packet: type 53
debug3: input_userauth_banner: entering
POWER FAILURE
Connection closed by 192.168.50.30 port 22
What is going on with the POWER FAILURE error?!? Has anyone seen this before?
thanks!
Potentially some files may have been corrupted that are required to process a login.
It probably will require a hands-on repair at the server console.
Definitely should be first rebooted locally then if logins are still not functional do the recovery.
The “POWER FAILURE” message seems to come from a motd after investigation, and the login failure is PAM related for all users except root.
nvm… it was a generated /etc/nologin file but still don’t know what created it. Maybe apcupsd
Look for NOLOGINDIR in /etc/apsupsd.conf.
POWER FAILURE is the most unhelpful default error message ever! 
It is something that “should” never (but too often does) happen to a server. I suppose it could say “hope you have backups!”. “POWER FAILURE” saves you from wondering if some software problem crashed the server.