MySQL/MariaDB – [ERROR] Plugin InnoDB registration as a STORAGE ENGINE failed error

I was migrating server and rsync all databases to new mariadb server. When tried to start mariadb on new server, I was getting this error:

Apr 24 18:30:26 my.server.com mysqld[9703]: 2018-04-24 18:30:26 140298644924544 [ERROR] Plugin 'InnoDB' init function returned error.
Apr 24 18:30:26 my.server.com mysqld[9703]: 2018-04-24 18:30:26 140298644924544 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
Apr 24 18:30:26 my.server.com mysqld[9703]: 2018-04-24 18:30:26 140298644924544 [Note] Plugin 'FEEDBACK' is disabled.
Apr 24 18:30:26 my.server.com mysqld[9703]: 2018-04-24 18:30:26 140298644924544 [ERROR] Unknown/unsupported storage engine: InnoDB
Apr 24 18:30:26 my.server.com mysqld[9703]: 2018-04-24 18:30:26 140298644924544 [ERROR] Aborting

Solution is to generate new ib_logfile0 and ib_logfile1 files. Just try steps bellow.

[root@lol ~]# cd /var/lib/mysql
[root@lol mysql]# mv ib_logfile0 ib_logfile0-backup 
[root@lol mysql]# mv ib_logfile1 ib_logfile1-backup
[root@lol mysql]# systemctl start mysql
[root@lol mysql]# mysql
Welcome to the MariaDB monitor.

It should work.

How to save mysql query output into a file

Sometimes you may want to save output of some mysql query to a text file. Maybe even to Excel’s spreadsheet file so that you have more control with editing, sorting … MySQL offers many useful options there.

Below is an example on how to save some mysql query output to csv file. You can terminate fields with some key character which is super useful. This example has fields terminated with ; and lines with \n.

mysql> select firstname, lastname, email, phone from clients INTO OUTFILE '/tmp/outputfile.csv' FIELDS TERMINATED BY ';' LINES TERMINATED BY '\n';

Just make sure that mysql has suitable permissions so that it will be able to write to a file – chmod 777.

How to change administrator username in WordPress

By default, WordPress won’t allow you to change username of  your administrator account. There are several ways to do this. There are even plugins for this, but I think using plugins for this task is unnecessary and bad idea in general. WordPress is great but consider using as less plugins as you can. Especially bad ones, they are just calling to be hacked by evil guys with too much time. 🙂

Here is how to change administrators username with one simple mysql command.

First, select your wordpress database.

mysql> show tables;
+-----------------------+
| Tables_in_sample-blog |
+-----------------------+
| wp_commentmeta        |
| wp_comments           |
| wp_links              |
| wp_options            |
| wp_postmeta           |
| wp_posts              |
| wp_snippets           |
| wp_term_relationships |
| wp_term_taxonomy      |
| wp_termmeta           |
| wp_terms              |
| wp_usermeta           |
| wp_users              |
+-----------------------+

So in this case I want to change username for my admin user.

mysql> select id, user_login from wp_users;
+----+------------+
| id | user_login |
+----+------------+
|  1 | admin      |
|  2 | someuser   |
+----+------------+

You just have to update user_login field in wp_users table with command below. Of course change id and user_login value to your needs.

mysql> update wp_users set user_login="igor" where id="1";
Query OK, 1 row affected (0.05 sec)
Rows matched: 1  Changed: 1  Warnings: 0

Username is now changed. You can login in your wordpress with new username.

mysql> select id, user_login from wp_users;
+----+------------+
| id | user_login |
+----+------------+
|  1 | igor       |
|  2 | someuser   |
+----+------------+

Create dump of specific tables from mysql database

You can simply create backups of specific tables with mysqldump.

mysqldump -u  -p  databasename table1 table2 table3 ... > mysqldump_file.sql

© 2018 geegkytuts.net
Hosted by Hosterdam


About author