The document provides instructions for installing an operating system from an ISO image file without burning it to a disc: 1. Create a folder to copy the ISO file to and mount the ISO file as a virtual CD-ROM. 2. Copy the kernel and initrd files from the mounted ISO to the installation folder. 3. Edit the GRUB configuration file to add an entry pointing to the kernel and initrd files to allow booting directly from the ISO without burning to disc. 4. Restart the system and select the new GRUB entry to start the installation process from the mounted ISO image.

1. Install OS using an iso image
1. Create a folder named “fedora” in root directory.
vishnu@VishnuRaj:/$ sudo mkdir fedora
2. Copy the iso image to the folder created in previous step.
vishnu@VishnuRaj:/$ sudo cp /media/vaio/fedora-image.iso /fedora/
3. Mount the iso image to CD-Rom.
vishnu@VishnuRaj:/$ sudo mount -o loop /fedora/fedora-image.iso /media/cdrom
4. Copy the kernel file named “vmlinuz” initrd file “initrd.img” from the mounted volume.
Path to copy these files are as follows,
Distributions Kernel initrd
Fedora /isolinux/vmlinuz /isolinux/initrd.img
Ubuntu /casper/vmlinuz /casper/initrd.gz
Mandriva /i586/isolinux/alt0/vmlinuz /i586/isolinux/alt0/all.rdz
OpenSUSE /boot/i386/loader/linux /boot/i386/initrd.gz
Debian /install.386/vmlinuz /install.386/initrd.gz
RHEL5 / CentOS /isolinux/vmlinuz /isolinux/initrd.img
5. Open the menu.lst file from /boot/grub/
vishnu@VishnuRaj:/$ sudo gedit /boot/grub/menu.lst
6. Add the following in menu.lst file
title Fedora 10 Installer
root (hd0,3)
kernel /fedora/vmlinuz
initrd /fedora/initrd.img
7. Restart the system and select the menu “Fedora 10 Installer” from grub menu to
install fedora-10.

2. To change the user password
sudo passwd <user-name>
To delete the user password
sudo sudo passwd -d <user-name>
To lock the user
sudo passwd -l <user-name>
To unlock the user
sudo passwd -u <user-name
To encrypt the file in vim editor
vim -x <file-name>
Use shell inside vim editor
To use shell
press Esc and :sh
To resume file
press ^d (ctrl+d)
Differentiate And Patch The File
To differentiate files and create patch file
diff -c oldprg.c newprg.c > prg.patch
To patch the File
patch oldprg.c < prg.patch
To open microsoft office 2007 (docx) file in OpenOffice Wordprocessor
$ sudo apt-get install libgif4 libungif4g

3. Split And Combine Big File
To split the file
For example, consider a file image.iso of size 600MB. We can split the file into 3 parts
of 200MB each.
split -b 200m image.iso
This creates xaa xab xac of 200m each.
To the splited files
cat xa* > newimage.iso
This combines the 3 files into a single iso file named “newimage.iso”.
Send Mail In Terminal
To check status of sendmail
vishnu@VishnuRaj:/etc/init.d$ sendmail status
To start sendmail option
vishnu@VishnuRaj:/etc/init.d$ sendmail start
Sending Mail
vishnu@VishnuRaj:~$echo “mail body” | mail -s “subject” <to-address>
Sending mail from text file
vishnu@VishnuRaj:/$mail -s “subject” to-address < mail-body.txt
Sending mail with attachment
vishnu@VishnuRaj:/$echo “mail body” | mutt -s “subject” -a fileattach.gif <to-address>

4. Adding Wallpapers To Boot Menu
1. Choose a picture and then load it into the GIMP (right-click and
select Open With -> Open with "GIMP Image Editor").
2. Right-click the image within GIMP and select Image ? Scale Image.
In the Width box, type 640 and hit the Tab key. The Height box
should then automatically change to 480.
3. Right-click the image again within The GIMP and select Image
->Mode -> Indexed and then type 14 into the Maximum Number of Colors box.
Then click the Convert button.
4. Right-click the image again within GIMP and select File -> Save
As. Give the file a name in the Name box, and use the .xpm file
extension.
5. Open a terminal window and type the following (this assumes the
file was saved to the desktop):
$ sudo mkdir /boot/grub/splashimages
$ gzip ~/Desktop/bootwallaper.xpm
$ sudo mv ~/Desktop/bootwallpaper.xpm.gz /boot/grub/splashimages
6. Replace bootwallpaper mentions above with the filename you chose.
7. Then open the boot menu file for editing in Gedit:
$ sudo gedit /boot/grub/menu.lst

5. 8. Look for the line that begins ## ## End Default Options ## and, below, add a new line.
splashimage=(hd0,3)/boot/grub/splashimages/bootwallaper.xpm.gz.
As above, replace bootwallpaper with the filename you chose. See Figure for an
example taken from my test PC. Save the file and then reboot to see the new wallpaper in
action.