I ran into the problem referred to in the subject line. It seems to be fairly common, to judge from stuff on the Internet, but none of the explanations or solutions offered there were of any help to me.
I run MySql 5.22 on a Mac desktop with El Capitan, but the MySQL installation is inherited from an earlier version of OS X. I stopped the server from the MySQL icon in the System Preferences panel, because I wanted to perform a proper binary backup and Dubois’ book said to stop the server especially if you are using INNO tables. When I restarted it with the restart seemed to work for a while but then aborted with the message “... ERROR! The server quit without updating PID file” As I understand it, the start and stop operations for MySQL server on the Mac changed between Yosemite and El Capitan. So it seems plausible to me that the server shut down according to one protocol and the way in which it shut down prevents it now from starting. I turned the computer on and off many times and the MySQL always automatically restarted, but I don’t remember ever stopping it from the MySQL icon in the Mac’s System preferences, and I suspect that using it was the cause of the malfunction. What can I do? One voice on the Internet suggested simply replacing the installation altogether, keeping the data directory and then updating the new data directory with the old one. If I read Paul Dubois’ MySQL manual correctly that should be OK. Because I made what he calls a “binary backup” and all my files are MyISAM or InnoDb and should be machine or version independent. I hesitate because on a previous occasion an older version of MySQL was extraordinarily difficult to get rid of and the machine in later installations seemed to remember a password that I had forgotten. In this case, I know the passwords. So, is the best thing to do 1) Move the data directory out of the current instllation 2) Get rid of the current installation 3) Replace the data directory of the new instllation with the old data directory Or are there problems and unknown dependencies in that approach? Martin Mueller Professor emeritus of English and Classics Northwestern University
