Note
By default, MySQL’s datadir is placed in the /var/lib/mysql directory. However, if you are planning on using MySQL tables to store a lot of data and your /var partition is small, it might cause you problem at a later stage. In such a scenario, it is better to move the MySQL’s datadir to another partition
Steps:
1. Stop your mysql server before starting this operation
2. Create the directories that will be new datadir
3. chown the directory to the mysql:mysql user
4. copy the files from the old datadir to the new location (cp -p : preserves ownership). However, make sure that the files
named ib_arch_log_0000000000, ib_logfile0 etc. are not copied to the newer location
5. Make sure that the files and directories are owned by mysql user
6. Make changes in the my.cnf to point the new datadir (datadir = /my/new/dir/)
7. Restart the MySQL database
8. Create a new database and verify that the files for this database are getting created in the new datadir (create database test)
9. After the server is running for a few days properly, get rid of the old data.