Comment 4 for bug 1071909

Oh, and about the files in /var/log/mysql you asked about.

While I'm running "dpkg --configure -a" (and don't stop it):

/var/log/mysql/error.log:
[lot's of lines, gets continuously longer]:
121110 17:48:56 InnoDB: Starting shutdown...
121110 17:48:57 InnoDB: Shutdown completed; log sequence number 2347290
121110 17:48:57 [Note]
121110 17:48:58 [Note] Plugin 'FEDERATED' is disabled.
121110 17:48:58 InnoDB: The InnoDB memory heap is disabled
121110 17:48:58 InnoDB: Mutexes and rw_locks use GCC atomic builtins
121110 17:48:58 InnoDB: Compressed tables use zlib 1.2.7
121110 17:48:58 InnoDB: Using Linux native AIO
121110 17:48:58 InnoDB: Initializing buffer pool, size = 128.0M
121110 17:48:58 InnoDB: Completed initialization of buffer pool
121110 17:48:58 InnoDB: highest supported file format is Barracuda.
121110 17:48:59 InnoDB: Waiting for the background threads to start
121110 17:49:00 InnoDB: 1.1.8 started; log sequence number 2347290
121110 17:49:00 [ERROR] Aborting

121110 17:49:00 InnoDB: Starting shutdown...
121110 17:49:01 InnoDB: Shutdown completed; log sequence number 2347290
121110 17:49:01 [Note]
121110 17:49:01 [Note] Plugin 'FEDERATED' is disabled.
121110 17:49:01 InnoDB: The InnoDB memory heap is disabled
121110 17:49:01 InnoDB: Mutexes and rw_locks use GCC atomic builtins
121110 17:49:01 InnoDB: Compressed tables use zlib 1.2.7
121110 17:49:01 InnoDB: Using Linux native AIO
121110 17:49:01 InnoDB: Initializing buffer pool, size = 128.0M
121110 17:49:02 InnoDB: Completed initialization of buffer pool
121110 17:49:02 InnoDB: highest supported file format is Barracuda.
121110 17:49:02 InnoDB: Waiting for the background threads to start

and the file /var/log/upstart/mysql.log contains lots of lines:
121110 17:58:09 [ERROR] Can't find messagefile '/usr/share/mysql/errmsg.sys'
^G/usr/bin/mysqladmin: connect to server at 'localhost' failed
error: 'Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)'
Check that mysqld is running and that the socket: '/var/run/mysqld/mysqld.sock' exists!
^G/usr/bin/mysqladmin: connect to server at 'localhost' failed
error: 'Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)'
Check that mysqld is running and that the socket: '/var/run/mysqld/mysqld.sock' exists!
^G/usr/bin/mysqladmin: connect to server at 'localhost' failed
error: 'Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)'
Check that mysqld is running and that the socket: '/var/run/mysqld/mysqld.sock' exists!
^G/usr/bin/mysqladmin: connect to server at 'localhost' failed
error: 'Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)'
Check that mysqld is running and that the socket: '/var/run/mysqld/mysqld.sock' exists!
121110 17:58:12 [ERROR] Can't find messagefile '/usr/share/mysql/errmsg.sys'