Installation and configuration of MySQL database under Linux CentOS6.4

Source: Internet
Author: User
Tags mysql client mysql version dmesg

First, MySQL Introduction

When it comes to databases, we mostly think of relational databases, such as MySQL, Oracle, SQL Server, and so on, which are very easy to install on Windows, and if you want to install a database on Linux, I have to recommend MySQL database first. And the first version of the MySQL database is distributed on Linux systems.

MySQL is a relational database management system developed by the Swedish MySQL AB company, currently owned by Oracle Corporation. MySQL is an associated database management system that keeps data in separate tables rather than putting all of the data in a large warehouse, which increases speed and increases flexibility. MySQL's SQL language is the most commonly used standardized language for accessing databases. MySQL software uses a dual licensing policy (this term "authorization policy"), it is divided into community and commercial version, because of its small size, speed, low total cost of ownership, especially the open source of this feature, the general small and medium-sized web site development has chosen MySQL as the site database. Thanks to the performance of its community edition, PHP and Apache make a good development environment.

To install MySQL database on Linux, we can download the MySQL database rpm package on its official website, Http://, Everyone can download the corresponding database files according to their operating system, the latest version is 5.6.10.

Here I am the installation of MySQL database through Yum, this way to install, can be related to MySQL some services, jar packages are installed to us, so save a lot of unnecessary trouble!!!

Second, uninstall the original MySQL

Because MySQL database is very popular on Linux, so the mainstream Linux version of the current download basically integrates the MySQL database inside, we can use the following command to see if the MySQL database is installed on our operating system

[[email protected] ~] # rpm -qa | grep mysql // This command will check whether the mysql database is installed on the operating system
If there is, we uninstall it with rpm -e command or rpm -e --nodeps command.

[[email protected] ~] # rpm -e mysql // Normal delete mode
[[email protected] ~] # rpm -e --nodeps mysql // Powerful delete mode, if you are prompted to rely on other files when you delete using the above command, you can use this command to force delete them
After deleting, we can use rpm -qa | grep mysql command to see if mysql has been uninstalled successfully! !!

Third, install mysql through yum

I use yum to install the mysql database. First, we can enter the yum list | grep mysql command to view the downloadable version of the mysql database provided on yum:

[[email protected] ~] # yum list | grep mysql
You can get the downloadable version information of the mysql database on the yum server:



Then we can install mysql mysql-server mysql-devel by entering the yum install -y mysql-server mysql mysql-devel command (note: when installing mysql, we did not install the mysql client, which is equivalent to installing the mysql database. (We need to install the mysql-server server)


[[email protected] ~] # yum install -y mysql-server mysql mysql-deve

After waiting for a while, yum will help us choose the software required to install the mysql database and some other attached software



We found that installing the mysql database through the yum method saves a lot of unnecessary trouble. When the following results appear, it means that the mysql database installation is successful.



At this point we can check the version of mysql-server just installed by using the following command


[[email protected] ~] # rpm -qi mysql-server

The mysql-server we installed is not the latest version. If you want to try the latest version, go to the mysql official website to download the rpm package and install it. At this point, our mysql database has been installed.

Fourth, the mysql database initialization and related configuration

After we install the mysql database, we will find that there will be an extra mysqld service. This is our database service. We can start our mysql service by entering the service mysqld start command.

Note: If this is the first time we have started the mysql service, the mysql server will first perform the initial configuration, such as:

[[email protected] ~] # service mysqld start

Initialize the MySQL database: WARNING: The host ‘xiaoluo’ could not be looked up with resolveip.
This probably means that your libc libraries are not 100% compatible
with this binary MySQL version. The MySQL daemon, mysqld, should work
normally with the exception that host name resolving will not work.
This means that you should use IP addresses instead of hostnames
when specifying MySQL privileges!
Installing MySQL system tables ...
Filling help tables ...

To start mysqld at boot time you have to copy
support-files / mysql.server to the right place for your system

To do so, start the server, then issue the following commands:

/ usr / bin / mysqladmin -u root password ‘new-password’
/ usr / bin / mysqladmin -u root -h xiaoluo password ‘new-password’

Alternatively you can run:
/ usr / bin / mysql_secure_installation

which will also give you the option of removing the test
databases and anonymous user created by default. This is
strongly recommended for production servers.

See the manual for more instructions.

You can start the MySQL daemon with:
cd / usr; / usr / bin / mysqld_safe &

You can test the MySQL daemon with
cd / usr / mysql-test; perl

Please report any problems with the / usr / bin / mysqlbug script!

Starting mysqld: [OK]

At this time, we will see a lot of information after starting the mysql server for the first time, the purpose is to initialize the mysql database. When we restart the mysql service again, we will not be prompted so much information, such as:


[[email protected] ~] # service mysqld restart
Stop mysqld: [OK]
Starting mysqld: [OK]

When we use the mysql database, we have to start the mysqld service first. We can use the chkconfig --list | grep mysqld command to check whether the mysql service starts automatically when it is turned on, such as:


[[email protected] ~] # chkconfig --list | grep mysqld
mysqld 0: close 1: close 2: close 3: close 4: close 5: close 6: close

We found that the mysqld service does not start automatically when it is turned on. Of course, we can set it to start by using the chkconfig mysqld on command, so that we do not have to manually start it each time


[[email protected] ~] # chkconfig mysqld on
[[email protected] ~] # chkconfig --list | grep mysql
mysqld 0: Disable 1: Disable 2: Enable 3: Enable 4: Enable 5: Enable 6: Disable

After the mysql database is installed, there will only be a root administrator account, but the root account has not yet been set a password for it. When the mysql service is started for the first time, some initialization of the database will be performed. In the message, we see a line like this:


/ usr / bin / mysqladmin -u root password ‘new-password’ // Set a password for the root account

So we can use this command to set a password for our root account (note: this root account is the mysql root account, not the Linux root account)


[[email protected] ~] # mysqladmin -u root password ‘root’ // Use this command to set the root account password to root

At this point we can log in to our mysql database through the mysql -u root -p command


Five, the main configuration file of the mysql database

1./etc/my.cnf This is the main configuration file for mysql

We can check some information of this file

[[email protected] etc] # ls my.cnf

[[email protected] etc] # cat my.cnf
datadir = / var / lib / mysql
socket = / var / lib / mysql / mysql.sock
user = mysql
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links = 0

log-error = / var / log / mysqld.log
pid-file = / var / run / mysqld /
2./var/lib/mysql Database file storage location of the mysql database

The database files of our mysql database are usually stored in the / ver / lib / mysql directory


[[email protected] ~] # cd / var / lib / mysql /
[[email protected] mysql] # ls -l
Total dosage 20488
-rw-rw ----. 1 mysql mysql 10485760 April 6 22:01 ibdata1
-rw-rw ----. 1 mysql mysql 5242880 April 6 22:01 ib_logfile0
-rw-rw ----. 1 mysql mysql 5242880 April 6 21:59 ib_logfile1
drwx ------. 2 mysql mysql 4096 April 6 21:59 mysql // These two are the two default database files when the mysql database is installed
srwxrwxrwx. 1 mysql mysql 0 April 6 22:01 mysql.sock
drwx ------. 2 mysql mysql 4096 April 6 21:59 test // These two are the default two database files when the mysql database is installed

We can create a database by ourselves to verify the storage location of the database file


Create our own database:
mysql> create database xiaoluo;
Query OK, 1 row affected (0.00 sec)

[[email protected] mysql] # ls -l
Total dosage 20492
-rw-rw ----. 1 mysql mysql 10485760 April 6 22:01 ibdata1
-rw-rw ----. 1 mysql mysql 5242880 April 6 22:01 ib_logfile0
-rw-rw ----. 1 mysql mysql 5242880 April 6 21:59 ib_logfile1
drwx ------. 2 mysql mysql 4096 April 6 21:59 mysql
srwxrwxrwx. 1 mysql mysql 0 April 6 22:01 mysql.sock
drwx ------. 2 mysql mysql 4096 April 6 21:59 test
drwx ------. 2 mysql mysql 4096 April 6 22:15 xiaoluo /// This is the xiaoluo database we just created ourselves
[[email protected] mysql] # cd xiaoluo /
[[email protected] xiaoluo] # ls
3./var/log storage location of the mysql database log output

Some log output storage locations of our mysql database are in the / var / log directory

[[email protected] xiaoluo] # cd
[[email protected] ~] # cd / var / log
[[email protected] log] # ls
amanda cron maillog-20130331 spice-vdagent.log
anaconda.ifcfg.log cron-20130331 mcelog spooler
anaconda.log cups messages spooler-20130331
anaconda.program.log dirsrv messages-20130331 sssd dmesg mysqld.log tallylog
anaconda.syslog dmesg.old ntpstats tomcat6
anaconda.xlog dracut.log piranha wpa_supplicant.log
anaconda.yum.log gdm pm-powersave.log wtmp
audit httpd ppp Xorg.0.log
boot.log ibacm.log prelink Xorg.0.log.old
btmp lastlog sa Xorg.1.log
btmp-20130401 libvirt samba Xorg.2.log
cluster luci secure Xorg.9.log
ConsoleKit maillog secure-20130331 yum.log

The mysqld.log file is where we store some log information generated by our operations with the mysql database. By viewing this log file, we can get a lot of information


Because our mysql database is accessible through the network, not a stand-alone version of the database, the protocol used is tcp / ip protocol, we all know that the port number bound to the mysql database is 3306, so we can use the netstat -anp command Let's see if the Linux system is listening on port 3306:

The result is shown above. The 3306 port number monitored by the Linux system is our mysql database! !! !! !!

Installation and configuration of Mysql database under Linux CentOS6.4

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