Speedup unit tests by moving MySql data to memory [Ubuntu]

There are several ways to speedup slow unit tests which interact with database:

Refactor code and tests and do not interact with db in unit tests
Use sqlite db in memory instead of MySql
Use MySql MEMORY engine
Move MySql data to memory

It is better to try other listed approaches and I think of last method as of quick temporary hack, but here it is:

stop mysql
move /var/lib/mysql to /dev/shm/mysql
link /var/lib/mysql to /dev/shm/mysql
start mysql

In Ubuntu there is also a problem with apparmor which will not allow mysql to read from /dev/shm. To fix this it is recommended to add following to the /etc/apparmor.d/usr.sbin.mysqld:

    /dev/shm/mysql/ r,
    /dev/shm/mysql/** rwk,

But it doesn’t work for me and I disabled apparmor for mysql (not recommended):

sudo mv /etc/apparmor.d/usr.sbin.mysqld /etc/apparmor.d/disable

Below are shell scripts to move MySql data to /dev/shm and back, restore backed up data and check db state.

Move db to memory script

    #!/bin/sh
    #Check if run as root
    if [ `whoami` != root ]
    then
        echo "You must be root to do that!"
        exit 1
    fi

    service mysql stop
    if [ ! -s /var/lib/mysql.backup ]
    then
        cp -pRL /var/lib/mysql /var/lib/mysql.backup
    fi
    mv /var/lib/mysql /dev/shm/mysql
    chown -R mysql:mysql /dev/shm/mysql
    ln -s /dev/shm/mysql /var/lib/mysql
    chown -h mysql:mysql /var/lib/mysql
    service mysql start

Move db to disk script

    #!/bin/sh
    #Check if run as root
    if [ `whoami` != root ]
    then
        echo "You must be root to do that!"
        exit 1
    fi

    service mysql stop
    rm /var/lib/mysql
    if [ ! -s /dev/shm/mysql ]
    then
        cp -pRL /var/lib/mysql.backup /var/lib/mysql
    else
        mv /dev/shm/mysql /var/lib/mysql
    fi
    service mysql start

Restore db backup script

    #!/bin/sh
    #Check if run as root
    if [ `whoami` != root ]
    then
        echo "You must be root to do that!"
        exit 1
    fi

    service mysql stop
    if [ ! -s /var/lib/mysql.backup ]
    then
        exit -1
    fi
    rm /var/lib/mysql
    cp -pRL /var/lib/mysql.backup /var/lib/mysql
    rm -rf /dev/shm/mysql
    service mysql start

Check db state script

    #!/bin/sh
    #Check if run as root
    if [ `whoami` != root ]
    then
        echo "You must be root to do that!"
        exit 1
    fi

    if [ -L /var/lib/mysql ]
    then
        echo "Mem db"
        exit 0
    else
        echo "File db"
        exit 1
    fi