Hadoop learning; JDK installation, Workstation Virtual Machine V2V migration; Ping network communication between virtual machines and cross-physical machine; Disable firewall and check Service Startup in centos of virtualbox

Install JDK in Ubuntu and configure Environment Variables

Preparations:
Find the JDK and configure the TXT file and copy it to the desktop instead of a directory. Instead, copy the file to the desktop.
Copy and paste the following command.
1. Configure the root user
Use the shortcut key CTRL + ALT + T to open the terminal
Enter the command: sudo passwd Root
Enter 123456 in the field where you need to enter the password (note that it is not displayed on the screen when you need to input three times each time)
2. Enable the root user
Enter the command su root on the terminal.
Enter Password: 123456
3. Install the JDK File
Input: CP/home/student/desktop/JDK. bin/usr/

// JDK. Bin is your JDK name.
Press ENTER;
Input: CD/usr/
Press ENTER;
Input: sudo sh JDK. Bin
Press ENTER;

// There may be a lot of nonsense in front, so you will keep entering

4. Configure the environment
Input: sudo gedit/etc/profile
Press ENTER;

After the command is entered, a text modifier is displayed.


Add at the end of the file? Java environment variable: copy the following four lines of commands to the end of the file:

Export java_home =/usr/jdk1.6.0 _ 45


Export jre_home =/usr/jdk1.6.0 _ 45/JRE


Export classpath =.: $ java_home/lib: $ jre_home/lib: $ classpath


Export Path = $ java_home/bin: $ jre_home/bin: $ path

Then save (CTRL + S)


5. Update the configuration file and verify it.
Finally, update the profile file.
Enter the command: Source/etc/profile
Press ENTER;
Install JDK and execute/etc/profile. Sometimes the command source/etc/profile is not powerful. You can directly execute the command on a graphical interface and wait for a while to see the result.

Finally, verify that JDK is successfully installed:
Input: Java-version


I plan to use workstation to build three virtual machines as a hadoop cluster. I used three physical machines. But I don't know how to do this. A physical machine is faulty, and hadoop2.0 was previously set up, change to 1.0 this time, learn first and then learn to run

V2V between virtual machines, directly find the file and copy it to another physical machine, and you can directly call it over there.

Communication between virtual machines. The solution we use is to connect the Virtual Machine bridge to the physical network, occupying the IP address of the physical LAN, to achieve communication between the virtual machine and the physical machine and cross-Physical Machine Communication.

Build a virtual machine again, this time using virtualbox

View Firewall

Disable Firewall

The chkconfig -- LIST command is used to view all the services in the system. If there is an on command, the startup is triggered in some cases. All disabled here

Hadoop learning; JDK installation, Workstation Virtual Machine V2V migration; Ping network communication between virtual machines and cross-physical machine; Disable firewall and check Service Startup in centos of virtualbox