What does MySQL Error 2013 mean?

This could be very bad, 2013 means that the thread servicing the mysqldump process has died. This could be because the InnoDB engine on the server has detected an error while reading the database file for you database. As mysqldump has to read all the pages for all of your database to make the backup it is likely to trigger any latent corruption that your application may avoid during it day to day activity.

If you run your mysql command and it reports that your connection id is a low number then you server has probably restarted itself. You should check your mysqld.log immediately to find out why.

2013 means that the connection to the server went away. There are several possibilities off hand:

1. Someone KILLed the query
2. Network problems caused the connection to die
3. The server crashed/died
4. Your connection was idle for wait_timeout and was killed
5. The client wasn't pulling data fast enough for net_wait_timeout and was killed