I recently encountered this problems. This problems seem to have been caused by my action to command “apt-get upgrade” on my server of debian 7 (wheezy) dist-pacage(version 7.10). The problems consist of two phenomenon  shown following.

• mysql-server becomes unable to be started due to some errors of InnoDB.
• If your case is that you can start the service process of mysql-server, however, you can’t stop the process.

The first issue has been solved thanks to the following article.

=> MySQL server won’t install to a new os (Debian, Ubuntu)

The second issue will be left even if you’ve got success by the above article. The second one has been solved thanks to the following article.

=>  MySQL: “Access denied for user ‘debian-sys-maint’@’localhost’”

I appreciate that those two articles being posted. I thank the authors.