Innodb: Operating System Error number 5 in MySQL
Given the log indication of starting recovery, then getting a failed read, this sounds consistent with a hard drive failure. You can see the same output with that as the diagnosis at http://forum.parallels.com/pda/index.php/t-70181.html and https://serverfault.com/questions/315664/mysql-wont-start, with the first answer in that second link showing a way to recover.