Enable innodb_file_per_table

innodb_file_per_table is by default ON Mysql 5.6.6 and onwards. There is plenty of stuff on Google about pros & cons ofinnodb_file_per_table.
This post details how to enable innodb_file_per_table on an existing database. Because innodb_file_per_table affects new tables only, created after innodb_file_per_table is enabled, we need to recreate old databases to force innodb_file_per_table on old tables and reclaim some disk space.

Backup First

Create a dir to take backups:

cd ~
mkdir backup
cd backup

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How to Back Up MySQL Databases

While automated backups are important, sometimes you just want to take a quick and dirty snapshot before making a change to your data.

Creating A Backup

The mysqldump command is used to create textfile “dumps” of databases managed by MySQL. These dumps are just files with all the SQL commands needed to recreate the database from scratch. The process is quick and easy.
If you want to back up a single database, you merely create the dump and send the output into a file, like so:
mysqldump database_name > database_name.sql
Multiple databases can be backed up at the same time: Read More

How To Install MySQL / MariaDB on CentOS 7

MariaDB is a drop-in replacement for MySQL. It is easy to install, offers many speed and performance improvements, and is easy to integrate into most MySQL deployments. Answers for compatibility questions can be found at: MariaDB versus MySQL – Compatibility. MariaDB offers more storage engines than MySQL, including Cassandra (NoSQL, in MariaDB Version 10), XtraDB (drop-in replacement for InnoDB), and OQGRAPH (in MariaDB Version 10).

Pre-Flight Check
  • These instructions are intended for installing MariaDB on a single CentOS 7 node.
  • I’ll be working from a Liquid Web Self Managed CentOS 7 server, and I’ll be logged in as root.

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CentOS 7 reset mysql password

Set / change / reset the MySQL root password on Linux. Enter the following lines in your terminal.
Step # 1 : Stop mysql service
systemctl stop mariadb
Step # 2: Start to MySQL server w/o password:
mysqld_safe –skip-grant-tables &
Step # 3: Connect to mysql server using mysql client:
mysql -u root Read More

How to install OTRS 4 on CentOS 7

In this post I’m going to walk you through installing OTRS 4 on CentOS 7. The procedure will be very similar for Red Hat Enterprise Linux (RHEL) version 7 as this is binary compatible.
Please note that there are some differences between CentOS 6 and CentOS 7: it now ships with systemd and with firewalld so the instructions to install OTRS are pretty different.
Setting up your production server or migrating from one is something you don’t want to do every day. This means you better take a distribution that will receive security upgrades for a long time. This is why I would recommend CentOS version 7 over version 6 at this point in time. Read More