Oracle VM VirtualBox Manager

to install linux ubuntu, go and download iso files :

Internet Connection on VM

I was having the same problem on Ubuntu 12.10 64bit using Virtualbox 4.2.22. Here are the steps I took to solve my problem:

Open Virtualbox Manager

  • Select the machine you cannot get internet on in the left pane
  • Click the Settings button in the top menu
  • Click Network in the left pane in the settings window
  • Switched to Bridged Adapter in the Attached to drop-down menu
  • Select the name of the network adapter you are currently using on your host machine. I am using wireless so I chose eth0 which is my wireless network adapter. You can check which adapter you are currently using by opening the terminal (CTRL+ALT+T by default) and running ifconfig. It will probably be the eth adapter that shows an inet addr and shows data transfer next to RX bytes.
  • Under Advanced, make sure the machine is using the Desktop Adapter Type
  • Under Advanced, make sure Promiscuous Mode is set to Allow VMs
  • Under Advanced, make sure Cable connected is checked on
  • Hit OK to save your changes
  • Start your VM

to remote access

remove OpenSSH: Code:

sudo apt-get remove openssh-client openssh-server

install OpenSSH again: Code:

sudo apt-get install openssh-client openssh-server


The reason is that recent Ubuntu installation (maybe others also), mysql is using by default the UNIX auth_socket plugin.

Basically means that: db_users using it, will be "auth" by the system user credentias. You can see if your root user is set up like this by doing the following:

$ sudo mysql -u root # I had to use "sudo" since is new installation

mysql> USE mysql;
mysql> SELECT User, Host, plugin FROM mysql.user;

| User             | plugin                |
| root             | auth_socket           |
| mysql.sys        | mysql_native_password |
| debian-sys-maint | mysql_native_password |

As you can see in the query, the root user is using the auth_socket plugin

There are 2 ways to solve this:

  • You can set the root user to use the mysql_native_password plugin
  • You can create a new db_user with you system_user (recommended)

Option 1:

$ sudo mysql -u root # I had to use "sudo" since is new installation

mysql> USE mysql;
mysql> UPDATE user SET plugin='mysql_native_password' WHERE User='root';
mysql> exit;

$ service mysql restart

Option 2: (replace YOUR_SYSTEM_USER with the username you have)

$ sudo mysql -u root # I had to use "sudo" since is new installation

mysql> USE mysql;
mysql> UPDATE user SET plugin='auth_socket' WHERE User='YOUR_SYSTEM_USER';
mysql> exit;

$ service mysql restart

Remember that if you use option #2 you'll have to connect to mysql as your system username (mysql -u YOUR_SYSTEM_USER)

Note: On some systems (e.g., Debian stretch) 'auth_socket' plugin is called 'unix_socket', so the corresponding SQL command should be: UPDATE user SET plugin='unix_socket' WHERE User='YOUR_SYSTEM_USER';

error: mysqld_safe Directory '/var/run/mysqld' for UNIX socket file don't exists.

sudo mkdir -p /var/run/mysqld
sudo chown mysql:mysql /var/run/mysqld

MySql case sensitive table names issue on Windows/MacOS to Linux

/etc/mysql/my.cnf file (add the row lower_case_table_names=1)


  • lower_case_table_names=0 > table names are stored as specified and comparisons are case sensitive.
  • lower_case_table_names=1 > table names are stored in lowercase on disk and comparisons are not case sensitive.
  • lower_case_table_names=2 > table names are stored as given but compared in lowercase.
lower_case_table_names = 1


to install vim editor

sudo apt install vim

replication mysql

How to fix master and slave have equal MySQL server UUIDs MySQL Error

if you get error on slave database like below

# mysql -u root -p
#mysql> show slave status;

Last_IO_Error: Fatal error: The slave I/O thread stops because master and slave have equal MySQL server UUIDs; these UUIDs must be different for replication to work.

Problem : Server UUIDs is automatically generated but it was copied when I cloned mysql instance using AWS AMI

ubuntu@ip-172-31-26-201:/var/lib/mysql$ cat /var/lib/mysql/auto.cnf

It can be simply fixed by removing that auto generated auto.conf file and restart MySQL server.

Enjoy your MySQL Master-Slave replication!!!