linux: full storage and expired password

i have a box that expires user passwords at a set interval for security purposes. one day one of the services running on that box halted. so i logged in remotely to check. i was asked to change may already expired password BUT its storage is already full, hindering the box from updating its passwords file. it's a deadlock.

to regain the box, i went to its physical location, unplugged the box, plugged it again, and tried changing my password as fast as i can. i was hoping the system would let go some log files and acquire disk space just enough for it to update its password file. it worked!

now i know that full storage and password expiry don't work well together. especially when your box is located in a different city!