Good Fedora Online Guide

Finally one good site for all thing Fedora
http://www.my-guides.net/en/content/view/59/26

Using httping to test http throughput and latency

To test the throughput and latency of a web server from a remote server, you can use the following utilities httping.

Step 1:
Install RPMForge

Step 2:
# yum install httping

Step 3:
# httping -c10 -Grg http://www.yourwebserver.com

Notes:
-g (URL to probe)
-G (GET request, to fetch the whole page)
-r (Resolve the hostname once, removing latency)
-b (show the transfer rates in bytes)
-s (display return codes)
-l (connect using SSL)

Red Hat Summit 2010 Presentations slides

A good respository of latest technologies presentation slides that was presented at Boston 2010. See Red Hat Summit Presentations

Using Yum Provides

This is a continuation of Using Yum effectively (Part 1) and Using Yum effectively (Part 2)

I have learned a cool command line "yum provides". "yum provides" help you search for the packages that will install either a file or directory. For example

# yum provides bash

bash-3.2-24.el5.x86_64 : The GNU Bourne Again shell (bash) version 3.2
Repo : base
Matched from:

bash-3.2-24.el5.x86_64 : The GNU Bourne Again shell (bash) version 3.1.
Repo : installed
Matched from:
Other : Provides-match: bash

Using yum effectively (Part 2)

This is the 2nd part of using yum effectively. See information Using yum effectively (Part 1)

There is one utility seldom used which is part of yum ie yumdownloader. Yumdownloader is a cool utility to download the rpm package instead of installing directly

Using yumdownloader# yum install yum-utils (download the yum-utils package)
# yumdownloader (package-name)
# yumdownloader alpine (For example)
# yumdownloader --source (package-name) (source packages)


Using the GUI yum installer
# yum install pirut
# pirut

Using yum effectively (Part 1)

Yum (Yellow Dog Updater, Modified) is used by CentOS, RHEL, Fedora an an interface to the underlying rpm system.

Some important usages:

1. To install package
# yum install (package-name)
# yum -y install (package-name)


2. To update package
# yum update (package-name)

Launch the GUI for yum update
# yum install pirut
# pup


3. To use yum to install instead of rpm.
(Yum will search for dependencies and repositories)
# yum localinstall (package-name)


4. Uninstalling Package
# yum remove (package-name)


5. Listing Package
# yum list (package-name)


6. Group Install
# yum groupinstall (group-package-name)

Xen: Invalid Source and/or Image destination

Xen Virtualisation comes with Redhat Enterprise 5 and its variant such as CentOS 5. A pretty cool package which allow full and para Virtualisation.


Very clear instruction can be found at Virtualization Guide


However during installation, I encounter a error where somehow I cannot install Media URL. I've tried NFS, but it didn't work.



















To resolve this issue, look at the CentOS Discussion Forum. Initially I tried to use iso image but couldn't get it to work

1. Start the Apache Service
2. Place the CentOS DVD Disk into the Drive
3. Do a Softlink from "ln -s /media/CentOS_5.2_Final /var/www/html/dvd"
4. Of course first check that you can see the http://127.0.0.1/dvd
5. Run Virt-Manager

The rest will be quite a breeze

Red Hat Enterprise Linux / CentOS Linux Enable EPEL (Extra Packages for Enterprise Linux) Repository

EPEL (Extra Packages for Enterprise Linux) is a volunteer-based community effort from the Fedora project to create a repository of high-quality add-on packages that complement the Fedora-based Red Hat Enterprise Linux (RHEL) and its compatible spinoffs, such as CentOS and Scientific Linux.
EPEL provide lots of packages for CentOS / RHEL, It is not part of RedHat or CentOS but is designed to work with these major distributions. Please note that EPEL only provides free and open source software unencumbered by patents or any legal issues. In short you will not find mp3, dvd and music / media player under EPEL. However, you will find many programs related to networking, monitoring, sys admin, programming and so on.
Packages are supplied in RPM format and in most cases are ready to use. Beware that some packages may break something and you should not blindly install those packages.
To enable EPEL for CentOS 5
For 32-bits
# rpm -Uvh http://download.fedora.redhat.com/pub/epel/5/i386/epel-release-5-4.noarch.rpm
For 64-bits
# rpm -Uvh http://download.fedora.redhat.com/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm
To enable EPEL for CentOS 4For 32-bits
# rpm-Uvh http://download.fedora.redhat.com/pub/epel/4/i386/epel-release-4-10.noarch.rpm
For 64-bits
# rpm-Uvh http://download.fedora.redhat.com/pub/epel/4/x86_64/epel-release-4-10.noarch.rpm

How to setup new Harddisk on LINUX

Here's a quick tutorial on how to setup new harddisk on linux taken from "Adding a Hard Disk in LINUX" by Erik Rodriguez

Step 1: First check after the Harddisk is installed, can it found under /dev/sdb or /dev/sdc. If yes. This means that the new HDD device has been detected

Step 2: Set up the Partition
# fdisk /dev/sdb

Step 2a: Go to Fdisk menu

Command (m for help): m
Command action
a   toggle a bootable flag
b   edit bsd disklabel
c   toggle the dos compatibility flag
d   delete a partition
l   list known partition types
m   print this menu
n   add a new partition
o   create a new empty DOS partition table
p   print the partition table
q   quit without saving changes
s   create a new empty Sun disklabel
t   change a partition's system id
u   change display/entry units
v   verify the partition table
w   write table to disk and exit
x   extra functionality (experts only)

Command (m for help):

Step 2b: Print Existing Partition

Command (m for help): p

Disk /dev/sdb: 50.0 GB, 50019202560 bytes
255 heads, 63 sectors/track, 6081 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot    Start       End    Blocks   Id  System

Command (m for help):

Step 2c: Create New Partition

Command (m for help): n
Command action
e   extended
p   primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-6081, default 1): 1
Last cylinder or +size or +sizeM or +sizeK (1-6081, default 6081): 6081

Command (m for help)

Step 2d: Check the the print Partition Specification which we have entered.

Command (m for help): p

Disk /dev/sdb: 50.0 GB, 50019202560 bytes
255 heads, 63 sectors/track, 6081 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot    Start       End    Blocks   Id  System
/dev/sdb1             1      6081  48845601   83  Linux

Command (m for help): 

Step 2e: Finalise the Partition

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

Step 3: Format the Disk
# mkfs -t ext3 /dev/sdb1

mke2fs 1.32 (09-Nov-2002)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
6111232 inodes, 12211400 blocks
610570 blocks (5.00%) reserved for the super user
First data block=0
373 block groups
32768 blocks per group, 32768 fragments per group
16384 inodes per group
Superblock backups stored on blocks:
     32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
     4096000, 7962624, 11239424

Writing inode tables: done                         
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 38 mounts or

180 days, whichever comes first.  Use tune2fs -c or -i to override.

Step 4: Mount the File System
# mount /dev/sdb1 /home1 (assuming /home1 has been created)

How to Install CentOS PXE server

A good and comprehensive article on How to install CentOS PXE Server by shirwablog.com