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How to Set Up DNS Lookup in Linux

Q. How do I setup DNS Lookup under any Linux distribution ?
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Red Hat / CentOS Setup Routing Metric For Network Device

Q. How do I set the routing metric on my network device under Fedora / RHEL / Red Hat / CentOS Linux server / workstation operating system?
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FreeBSD List All Outdated Package

Q. How do I know what packages are available to be updated on my FreeBSD Server system? How do I list all outdated packages under FreeBSD / OpenBSD operating system?
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What do I do if my Linux Server / Workstation does not boot?

Q. I'm using Debian Linux and CentOS operating system. My question is what do I do if my server refused to boot? How do I troubleshoot the problem?

A. Usually most Linux distribution provides rescue mode. It allows to access to disk partition and you are allowed to solve the problem.

To use the rescue mode of the install CD, follow these steps:
a) Boot from 1st CD / DVD media

b) Enter rescue at the prompt. (use 'dd rescue' if you need to load the SCSI driver)

c) You will get at a shell prompt. Now you can reinstall boot loader or check disk for errors and so on.

Please note that Linux distributions such as Mandriva or Ubuntu Linux offers menu based troubleshooting options. See our previous articles for detailed instructions:

Find Linux / UNIX Kernel Version Command

How do I find out what kernel version I am currently running under Debian Linux or any other Linux distribution using a shell prompt? How do I find out Unix kernel version?
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How to Update Ubuntu Linux

Q. How do I upgrade / update Ubuntu Linux to latest release or software such as 7.10 / Gutsy Gibbon?

A. Ubuntu 7.10 is the current version of the Ubuntu operating system. You can only directly upgrade to Ubuntu 7.10 ("Gutsy Gibbon") from Ubuntu 7.04 ("Feisty Fawn"). First apply all updates by Clicking System > Administration > Update Manager > Check Only apply updates

Once all updates installed, click on System > Administration > Update Manager > Check > A message will appear informing you of the availability of the new release
How to Update Ubuntu Linux
Click on Upgrade button > follow the on-screen instructions.

What Is Bourne Shell?

What is bourne shell?
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Howto: Linux Write protect a file

Q. How do I write protect a file under Linux? I’m using CentOS 5 server Linux operating system. I need prevent accidental changes to my files.

A. There are two ways to write protect a file under Linux.

Method #1: You can make file readonly by removing users’ write permission for a file. Under Linux and UNIX user cannot remove or modify file if they don’t have a write permission. You can use normal chmod command for this purpose.

Method #2 : You need to use chattr command which changes the file attributes on a Linux second extended (ext2 / ext3) file system. You need to setup i attribute. A file with the i attribute cannot be modified: it cannot be deleted or renamed, no link can be created to this file and no data can be written to the file. Only the superuser (root) or a process possessing the CAP_LINUX_IMMUTABLE capability can set or clear this attribute.

Write protecting a file using chmod command

Let say you want to write protect the file called data.txt so that no other users can change it, enter:
$ chmod go-w data.txt
To provide back permission use:
$ chmod go+w data.txt

Write protecting a file using chattr command

Let say you want to write protect the file called data.txt so that no other users can change it including root user, enter (you must login as the root user to use chattr command):
# chattr +i data.txt
To remove i attribute, enter:
# chattr -i data.txt

make buildworld cd: can’t cd to /usr/src/tools/build/make_check Error and Solution

'm trying buildworld under FreeBSD operating system. But I'm getting an error which read as follows:

>>> Building an up-to-date make(1)
cd: can't cd to /usr/src/usr.bin/make
*** Error code 2

Stop in /usr/src.
*** Error code 1

Stop in /usr/src.

How do I fix this problem?
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Arch Linux Disable IPv6 Networking

How do I disable IPv6 networking under Arch Linux?
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