MySQL database has been problem free for a few months. Today when I checked for upgradeable packages using the Synaptic Package Manager it came up with the various MySQL components (-common, -client, -server, etc). I therefore decided to upgrade (I forgot to note the installed version but think it was 5.6.21) to 5.6.25-1-ubuntu2.0.Afterwards when I went to query the database I got the message:-
Error occured: Can't connect to MySQL server on '127.0.0.1' (111)
I then found the server was not running. In the log file I fond that the message:-
Can't create file /var/lib/mysql/user.lower-test
I have spent an hour or so searching on line and although the issue has been reported previously I have not seen it in the context of a 'post-update' issue so unsure of my next step.