Failed to restart mysql.service: Unit mysql.service is masked

On starting the upgrade of Openstack to Kilo, I had a problem starting the mysql/MariaDB as I kept getting an error as follows:

root@ts036953:/home/pssuser# service mysql restart
Failed to restart mysql.service: Unit mysql.service is masked.


Solution:

root@ts036953:/home/pssuser# rm -r /var/lib/mysql*        # Remove any old database setup
root@ts036953:/home/pssuser# mysql_install_db -u mysql    # Install new database
root@ts036953:/home/pssuser# systemctl unmask mysql.service    # Emables the service for systemd
root@ts036953:/home/pssuser# service mysql start        # start the service.

dpkg-statoverride: error: an override for

You are trying to install a debian package (e.g. linux-image-3.16.0-31-generic_3.16.0-31.43~14.04.1_amd64.deb) with the following command:

root@ts037152:/home/pssuser# dpkg -i linux-image-3.16.0-31-generic_3.16.0-31.43~14.04.1_amd64.deb


=========================+ Start of output
... 
update-initramfs: Generating /boot/initrd.img-3.16.0-31-generic
W: mdadm: /etc/mdadm/mdadm.conf defines no arrays.
run-parts: executing /etc/kernel/postinst.d/pm-utils 3.16.0-31-generic /boot/vmlinuz-3.16.0-31-generic
run-parts: executing /etc/kernel/postinst.d/statoverride 3.16.0-31-generic /boot/vmlinuz-3.16.0-31-generic
dpkg-statoverride: error: an override for '/boot/vmlinuz-3.16.0-31-generic' already exists; aborting
run-parts: /etc/kernel/postinst.d/statoverride exited with return code 2
Failed to process /etc/kernel/postinst.d at /var/lib/dpkg/info/linux-image-3.16.0-31-generic.postinst line 1025.
dpkg: error processing package linux-image-3.16.0-31-generic (--install):
 subprocess installed post-installation script returned error exit status 2
...
=========================+ End of output

To resolve the statoverride error, run the following command:

root@ts037152:/home/pssuser# dpkg-statoverride --remove /boot/vmlinuz-3.16.0-31-generic

Then rerun your installation command for the package.

Hope that helps.

Yours truly,
J. Napo Mokoetle