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Disable SSLv2 and enable SSLv3 or TLSv1

SSL 2.0, reportedly suffers from several cryptographic flaws and has been deprecated for several years. An attacker may be able to exploit these issues to conduct man-in-the-middle attacks or decrypt communications between the affected service and clients. To disable SSLv2 follow these steps.

After performing vulnerability scan using nessus if you find details about SSLv2 weaknesses in that report then please find the options required to disable SSLv2 as mentioned below.

In /etc/httpd/conf.d/ssl.conf change following options

It is possible to create different files of any arbitrary size on a unix or linux machine using the "dd" command.

Below is an example:

$ cd /tmp
then execute following command.
$ dd if=/dev/zero of=testfile bs=1024 count=100

This above command will create a file of size 1024 * 100 bytes.

In this command the description about the syntax of command is as explained below,

* if = It is input file.
* of = It is output file or the file to be created, you can give any name.
* bs = It is the block size in bytes.
* count = It is the no of blocks of size bs.

Steps to configure network bonding in CentOS / Redhat / fedora

1. It is not necessary but good to run lspci | grep Eth command to list your ethernet port details.
2. setup ethernet channel bonding for redundant network connectivity. Add following lines in /etc/modprobe.conf

alias bond0 bonding
options bond0 mode=1 use_carrier=1 primary=eth0 miimon=100 downdelay=300 updelay=300

3. Create a ifcfg-bond0, ifcfg-eth0 and ifcfg-eth1 config file as explained below to hold your bonding configuration

DEVICE=bond0

You can follow steps listed below to extend logical volume assigned to para virtualized OS. You can also extend logical volume on which para virtualized OS is installed.

1. Login to Dom-0. become super user OR login as root to Dom-0.
2. Identify the logical volume you want to extend. e.g it is /dev/vg0/virtual00
3. execute following command to extend that logical volume.

lvextend -L+20G /dev/vg0/virtual00

4. run lvscan from command prompt and see whether you can see increased /dev/vg0/virtual00.

You can recover MySQL database server password with following five easy steps.

Step # 1: Stop the MySQL server process.

Step # 2: Start the MySQL (mysqld) server/daemon process with the --skip-grant-tables option so that it will not prompt for password

Step # 3: Connect to mysql server as the root user

Step # 4: Setup new root password

Step # 5: Exit and restart MySQL server

Here are commands you need to type for each step (login as the root user):

In Linux, as in most other Unix-like operating systems, it is common to use a whole partition of a hard disk for swapping. However, with the 2.6 Linux kernel, swap files are just as fast as swap partitions, although Red Hat recommends using a swap partition. The administrative flexibility of swap files outweighs that of partitions; since modern high capacity hard drives can remap physical sectors, no partition is guaranteed to be contiguous. You can add swap file as a dedicated partition or use following instructions to create a swap file.
Procedure to add a swap file

Steps to boot a PV-guestOS in to rescue mode

A. Create an installation tree and get it available through http or nfs for the guest OS. You can also your existing installation tree if available in your enviroment. It will look like this.

drwxr-xr-x 2 user user 532480 Mar 21 13:18 CentOS
-rw-r--r-- 8 root root 212 Nov 20 2007 EULA
-rw-r--r-- 8 root root 18009 Nov 20 2007 GPL
drwxr-xr-x 4 root root 2048 Mar 21 13:18 images
drwxr-xr-x 2 root root 2048 Mar 21 13:14 isolinux
drwxr-xr-x 2 root root 14336 Mar 17 23:19 NOTES

It is always very handy to set up your own local repository to prevent from downloading the remote repository over and over again. This tutorial shows how to create a CentOS mirror for your local network. If you have to install couple of or multiple systems in your local network then all needed packages can be downloaded over the fast LAN connection, thus saving your internet bandwidth and your valuable time.

Create the Directories:

mkdir -pv /var/www/html/centos/5/{base,updates}/i386

1. How to create local YUM repository
2. How to setup bonding in Centos
3. How to setup bonding in SUSE
4. How can I boot a PV-GuestOS into rescue mode?
5. How to add swap space on the fly

This is a list of things that all can easily do in GNU/Linux but find it hard or impossible to do in other desktop operating system.

* Connect more than four people across the internet to a graphical interface at the same time.
* Tinker around with the source code.
* Compile my own Linux from scratch.
* Have as many or as little programs installed as I want.
* Change every aspect of the user interface to suit my needs.