Friday 27 September 2013

ELA_05_Rescue_&_Single_User_Modes

Accessing Linux Partition using Rescue Disk

-> Boot the machine using rescue disk or Linux installation disk.
-> At the Installation wecome screen type "linux rescue"
-> Choose the language and keyboard type.
-> Select "No" at the screen asks to start the network interfaces on your machine.
-> Select "Continue" for rescue.
-> Select "OK" for rescue.
-> In the shell prompt if you wish to run the machine as root user's environment, run the below command.
# chroot /mnt/sysimage

Booting the system in Single User mode
-> While we turn the system ON, after the BIOS Power ON Self Test (POST) the GRUB screen appears.
-> At this screen interrupt the GRUB by pressing any key.
-> Select the "Red Hat Enterprise Linux (2.6.32.xxxx)" operating system.
-> Press 'e' to edit.
-> Here find the line with "kernel – vmlinuz............."
-> Select this line and press 'e' to edit this line.
-> At the end of the line give a space and type '1' or "single" and press return.
-> Press 'b' to boot with the kernel in single user mode.


Note: Be careful while doing any tasks in rescue or single user modes because you will be logged in as the root user. With out proper knowledge of rescue or single user modes there might be a chance to crashing the server.

Tuesday 24 September 2013

ELA_04_Installation

Red Hat 6 RHEL Installation
1. Select Install or upgrade an existing system option on Grub Menu

2. Select 'OK' to go for the DVD media test if you wish other wise select 'Skip'.

3. Graphical installation starts here. Select 'Next' from the welcome screen.

4. Choose a language

5. Choose a keyboard type

6. Choose the installation media – Basic for IDE and specialized for SCSI HDD's

7. In the Storage device warning screen select 'No, keep any data' if your HDD contains any data, otherwise select 'Yes, discard any data'.

8. Provide a hostname to identify the host on a network.

9. Select your timezone in my case i have choosen 'India/Kolkata'

10. Enter a password for the root user.

11. Select type of installation.

12. Choose Standard Partition to create a new filesystem or partition.

13. In Linux we need a minimum of two partitions
1. / - The root filesystem which should be a minimum of 8GB
2. Swap filesystem. It should be 1.5 to 2 times of your system memory(RAM).

14. Verify the created filesystem and select Next.

15. Writing changes (creating partitions) to disc

16. Configure boot loader options. Select device to install bootloader and check/create boot loader operating system list.
17. Select Desktop as your installation environment.

18. Starting installation process

19. Installation is complete
Click reboot computer and remove installation media.

Red Hat 6 RHEL Finishing Installation
20. Selecting RHEL 6 from grub

21. Booting Red Hat 6

22. Red Hat 6 Welcome screen appears and at the welcome screen click Forward.

23. Create normal user

24. Setup date and time and keep up-to-date with NTP

25. At the login screen of Red Hat 6 Gnome Desktop give your username and password.