Most of the time we need to check the mysql value set on server and most of the techs checks /etc/my.cnf file.If you want to check all values set in mysql on server. We can use following simple command.
mysqld –no-defaults –verbose –help
Archive for the Category »Mysql + phpmyadmin «
How to check mysql servers set values?
Category: Linux Administrator Interview Questions, Mysql + phpmyadmin
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phpmyadmin error “Cannot start session without errors”?
The most common problem in newly installed cPanel server is as follows after browsing the phpmyadmin problem.
“cannot start session without errors, please check errors given in your PHP and/or webserver log file and configure your PHP installation properly.”
To resolve above error you need to change the values in /usr/local/cpanel/3rdparty/etc/phpmyadmin/php.ini file.
root@gunjan[~]#pico /usr/local/cpanel/3rdparty/etc/phpmyadmin/php.ini
And than change the following values in php.ini file
FROM:
—–
session.save_handler = sqlite
session.save_path =/var/cpanel/userhomes/cpanelphpmyadmin/sessions/phpsess.sdb
—–
TO
—–
session.save_handler = files
session.save_path = /tmp
Note : To make change the values in php.ini you need to login into as root user.
Category: Mysql + phpmyadmin
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How to repair mysql database table manually?
You can repair the database table manually from shell by using following command.
root@gunjan[~]mysql>mysql –u databaseusername –p databasename
For example if we are using database gunjan_db
root@gunjan[~]mysql
mysql> use gunjan_db;
Database changed
mysql> show tables;
+———————————————+
| Tables_in_gunjan_db |
+———————————————+
| additional_images
| address_book
| address_format
| administrators
| banners
| banners_history
| cache
| categories
| categories_description
| configuration
| configuration_group
| counter
| orders_products
| orders_products_attributes
| orders_products_download
| c
| orders_status_history
| orders_total
For example we need to repair table orders_status
mysql> repair table orders_status;
+————————————+——–+———-+———-+
| Table | Op | Msg_type | Msg_text |
+————————————+——–+———-+———-+
| gunjan_db.orders_status | repair | status | OK |
+————————————+——–+———-+———-+
1 row in set (0.11 sec)
mysql> q
Bye
Category: Mysql + phpmyadmin
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Backup of mysql database using cron job.
To generate the backup of mysql database using cron job refer following three format as per your requirement.
1) Cron job to generate database backup in .sql format
* * * * * /usr/bin/mysqldump -u databaseusername databasename -ppassword > /path of database database.sql
2) Cronjob to compress database backup in .bz2 format
* * * * * /usr/bin/mysqldump -u datbaseusername databasename -pdatbasepassword|bzip2 -c > /path of database database.bz2
3) Cronjob to compress database backup in .gz format
* * * * * /usr/bin/mysqldump -u databaseusername databasename -ppassword|gzip > /path of databasedatabase.gz
If you have any problem or idea about this thread than contact me at nsk.gunjan@gmail.com
Category: Basic Linux, Cron jobs issue, Mysql + phpmyadmin
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mysql has failed, please contact the sysadmin (result was “mysql has failed”).
Now a most common problem we are facing with the mysql on newly installed server if we have mysql 5 we mostly receive following error message when starting mysql service from WHM
“mysql has failed, please contact the sysadmin (result was “mysql has failed”).”
As well as when ever we run mysql from shell its gives error message
“Access denied for user ‘root’@'localhost’ (using password: YES)”.
In that case we need to remove mysql from server and reinstall it by using following commands.
1)Login into server as root user
root@Gunjan [~]# which mysql
/usr/bin/mysql
root@Gunjan [~]#mv /usr/bin/mysql /usr/bin/mysql-back
root@Gunjan [~]mv /var/lib/mysql /var/lib/mysql-back
root@Gunjan [~]/scripts/mysqlup –force
Now reset the root password from WHM >> Main >> SQL Services >> MySQL Root Password
Now you will able to access mysql without any problem 
Some time above solution also not allowing to access mysql still throws following error message.
root@server[~]#mysql
“Access denied for user ‘root’@'localhost’
In that case refer following steps but carefully as it will cause you database loss.
root@server[~]#/etc/init.d/mysql stop
root@server[~]#mv /var/lib/mysql/ /var/lib/mysql-back
root@server[~]#mv /etc/my.cnf /etc/my.cnf-back
root@server[~]#/scripts/mysqlup –force
root@server[~]#/etc/init.d/mysql start
root@server[~]#mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1430564
Server version: 5.0.85-community MySQL Community Edition (GPL)
Type ‘help;’ or ‘\h’ for help. Type ‘\c’ to clear the current input statement.
mysql> \q
Bye
Now you can restore the databases from /var/lib/mysql-back to /var/lib/mysql
Category: Mysql + phpmyadmin
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How to set Sim link or Symbolic link?
Basically Sim link or Symbolic link is a type of File that contains a reference to another File/Directories in the form of an absolute and that affects path name.
The format for Sim link or Symbolic link is as follows
ln -s <file name> in the directory you want to make a link from.
For example
To set mysql Sim link or Symbolic link
ln -s ../../var/lib/mysql/mysql.sock mysql.sock
or
ln -s /var/lib/mysql/mysql.sock mysql.sock
You need to use above Sim link or Symbolic link as per your mysql setp.
Symbolic link,add Symbolic link,Sim link,add Sim link,what is Sim link
Category: Basic Linux, Mysql + phpmyadmin
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Simple php script to check database connection?
To check the database connection script you can use following code under your domain
<?php
mysql_connect(“localhost”, “admin”, “1admin”) or die(mysql_error());
echo “Connected to MySQL<br />”;
mysql_select_db(“test”) or die(mysql_error());
echo “Connected to Database”;
?>
After browsing the database connection script you will see following content if database connect to your server.
Connected to MySQL
Connected to Database
Category: Mysql + phpmyadmin
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MySql server error “Client does not support authentication protocol”.
After upgrade server to 5.1 generally we are getting following error message.
Client does not support authentication protocol requested by server; consider upgrading MySQL client.
The above error message are receiving because latest version of MySql uses a new format for the password in that case to use older client to use older version Mysql with new version Mysql you have to set the passwords on the server to their old format.Refer following steps to set the password.
Login into shell as root user and access mysql with root user and password
[root@gunjan.com]#mysql -u root -p
Then, copy and paste the following command in shell, editing commands if necessary, to change the password of the user to the old format.
[root@gunjan.com]#UPDATE mysql.user
[root@gunjan.com]#SET password=OLD_PASSWORD(‘password’)
[root@gunjan.com]#WHERE user=’username’
[root@gunjan.com]#AND host=’host’;
After running above commands flush the tables.
[root@gunjan.com]#flush privileges;
Then exit the mysql client.
[root@gunjan.com]#\q
It will sort your problems
Category: Mysql + phpmyadmin
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phpmyadmin shows old mysql version?
After upgrading mysql still showing old version then run following script on server
/scripts/makecpphp
Category: Mysql + phpmyadmin
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