Upgrade 7 to 7.2.2 hangs on starting mysql

My upgrade is stuck on the starting mysql screen.

I found some older references listing a few different issues, wanted to know what I should look at w/ this version and issue.

I had this happen recently.
You will find the upgrade script is repeatedly trying to start mysql, and it is repeatedly dying with errors.

Jump into another shell and see if you can have a look at the mysql logs which will tell what is wrong and hopefully let you fix it.