How do you configure MySQL to use block storage on Ubuntu 14.04?

July 13, 2016 928 views
MySQL Block Storage Ubuntu

Within /etc/mysql/my.conf, you can easily set datadir=/mnt/your_block/mysql, but there are some deeper issues with apparmor. How do I reconfigure apparmor to acknowledge my new datadir?

I've followed directions at this StackOverflow post, but upon completion I get ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/mnt/volume-nyc1-01/mysql/mysqld.sock'

I can't find mysqld.sock.

6 Answers
MelissaAnderson MOD July 21, 2016
Accepted Answer
Whether you’re adding more space for data or evaluating ways to optimize database performance, this tutorial will guide you through relocating MySQL’s data directory.

After you've undone the stackexchange suggestions, try looking at /etc/apparmor.d/usr.sbin.mysqld and updating the following stanza with the path to your mount:

# Allow data dir access
  /var/lib/mysql/ r,
  /var/lib/mysql/** rwk,

You'll also need to restart apparmor:

sudo /etc/init.d/apparmor restart

If systemd still squawks about not being able to find /var/lib/mysql when you try to restart mysql you might try creating a symlink between the mount point and the default location as follows (with the appropriate path to your new volume.)

sudo ln -s /volume-nyc1-01/mysql /var/lib/mysql
  • Thanks for the response, Melissa.
    To clarify, I should undo all suggestions found at the StackOverflow page?

    Do I still need to modify etc/mysql/my.cnf ?

Apologies. After a closer look at the directions in the StackExchange link you posted and the error you encountered, it looks like the problem may stem from the suggestion to set the socket value: socket=/array2/mysql/mysql.sock,

If you were to put that back to its original setting, the rest of the directions might work as written.


That was ineffective. Can DigitalOcean please publish an official tutorial for using MySQL or MariaDB or PostgreSQL w/ the new Block volumes?


  • It looks like maybe you got it running? Hopefully.

    Meanwhile, there is a tutorial in the works for moving the MySQL data directory to a new location to help people take advantage of Block Storage. I'll post a link when it's published.

I'm having no luck on Ubuntu 14.04. I followed the StackOverflow commands above and when I attempt to restart mysql I get:

2016-08-25 15:54:08 1909 [ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.user' doesn't exist

in the error log.

Is there an official DigitalOcean tutorial for 14.04?

Here are the commands I used (see reply above):

mkdir /mnt/disk002/mysql
cp -R /var/lib/mysql /mnt/disk002/mysql/
cp /etc/mysql/my.cnf /root/my.cnf.backup
emacs /etc/mysql/my.cnf

    #datadir        = /var/lib/mysql
    datadir = /mnt/disk002/mysql

chown -R mysql:mysql /mnt/disk002/mysql
mv /var/lib/mysql /var/lib/mysql-old
ln -s /mnt/disk002/mysql /var/lib/mysql 
echo "alias /var/lib/mysql/ -> /mnt/disk002/mysql/," >> /etc/apparmor.d/tunables/alias
sudo /etc/init.d/apparmor reload

start mysql
start: Job failed to start
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