An ISO is a file that contains the complete image of a disc, from sector 0 to the end. Such files are often used when transferring CDROM images over the Internet, and are commonly used as a way of offering Linux distributions for download. The latest version of the e-smith server and gateway, for example, is available from e-smith.org as a 335MB download. Once you have it on your hard drive, you can burn it onto CD using one of many CD-burning software packages.
More precisely, an ISO image is an image of an ISO 9660 CD-ROM. ISO is short for the International Organization for Standardization. (ISO is not an acronym. Instead, the name derives from the Greek word iso, which means equal.) The ISO 9660 format defines the file system used by almost all CDROMs of Windows, Mac, Linux and so on.
Some CD-burning applications create plain ISO 9660 images, while others interpret the ISO format as they like. Nero, from Ahead Software, uses the NRG suffix to name its ISO images. ISO images created by Easy CD Creator (from Roxio, Inc., which was spun off from Adaptec, Inc. in September, 2000) contain some lead-in and lead-out bytes around the core of the 2048-byte sector. This explains why ISO images created by Easy CD Creator cannot be burnt by all burning packages (for example, CDRWin complains about the file not beeing a multiple of the sector size). On the other hand, Easy CD Creator can burn plain ISO images written by other packages.
To create a bootable CD from an ISO image, you must burn the actual CD image onto the CD. Burning the ISO file to the CDROM will not produce a usable disc.
Take care to download the ISO in binary mode (FTP). By default, Netscape downloads the file in ASCII mode, which corrupts the image.
Do not operate any other programs while the CD is being written to.
Do not bump or nudge the CD burner while it is operating. Vibrations can cause the burning process to fail.
If you don't have a CD burner, find a Linux user group near you. Someone will be sure to help.
Before you burn your CD, it's a good idea to check the integrity of the e-smith ISO image you downloaded. You can do this quickly using md5sum. When you perform an md5sum check, you are comparing the unique 128-bit "signature" of the file you downloaded to the signature of the file on the server you downloaded from. If the md5 signatures match, you have an uncorrupted file.
To perform an md5sum check on your downloaded file, you need two things. The first is the md5sum program, which is included in all major Linux distributions; a free version for Windows, md5sum.exe, is available in the DOSWindowsApps contrib directory of our ftp site (see below for instructions).
The second thing you need is the unique md5 signature of the original file on the server from which you downloaded. This can be found in the same ftp directory as the iso image, in the file called md5sum.txt.
Make sure you are in the directory in which you saved the downloaded iso image.
At a command prompt, enter the command (where filename is the name of the iso file):
md5sum filename |
Compare this with the signature of the file on the server. If they are the same, you can be sure that the image on your computer is uncorrupted. If they differ, the image is corrupted and you will have to download it again.
Download md5sum.exe from the DOSWindowsApps contrib directory of our ftp site. If you are using Windows 95/98/Me, you should download to c:\windows\command. If you are using Windows NT/2000, you should download to c:\winnt\system32.
Open an MS-DOS window and change to the directory of the file you want to check.
When you are in that directory, enter the command (where filename is the name of the iso file):
md5sum filename |
Compare this with the signature of the file on the server. If they are the same, you can be sure that the image on your computer is uncorrupted. If they differ, the image is corrupted and you will have to download it again.
The method you use will depend on which CD writing software package you use. It's a good idea to consult the CD writing software's documentation before you start, because if you make a mistake you'll probably have to throw the disc out and start again.
Insert a blank CD into the CD writer.
Launch Easy CD Creator.
In the File menu, select "Create CD From Disk Image".
Browse to the location where the ISO image was saved on the hard drive.
Select ISO from File Type.
Select the ISO image file.
Click on OK.
Click on OK once again.
Insert a blank CD into the CD writer.
Launch Nero.
In the File menu, select "Burn CD image".
Choose as file type: all files (*.*), since Nero expects files with the NRG suffix.
Select the ISO image file.
You will see a dialog box asking if you want to supply detailed image parameters. Enter the following parameters:
Type of image: Data Mode 1
Block size: 2048 bytes per sector
File precursor and image trailer: 0 length
No scrambled and no Swapped.
Click on "burn". If the program complains that there are errors in the image file, click on the button "Ignore" and launch the burning.
You need to create a Track Image project in WinOnCD for the image file. Please note that the program doesn't accept the ISO suffix for the image, and that you'll have to rename it with the raw suffix.
Open the icon labeled "File Backup and Tools". In the listbox named "Backup/Tool Operation", select "Record an ISO 9660 Image File". In the box "ISO 9660 Image File", click on the button labeled "..." (Browse) and select the ISO image file. At the bottom of the dialog box, select CD-ROM and Mode 1. Then click the button labelled "START".
If you're planning to install the e-smith software on older computer that doesn't support booting off a CDROM, you'll have to make a boot floppy. Before you start, make sure you have handy a blank, formatted 1.44MB 3.5" diskette.
Insert the e-smith CD into your CD drive.
Doubleclick the "My Computer" icon on your Windows desktop.
Doubleclick the icon for your CD drive.
You should now see the contents of your e-smith CD. Doubleclick the dosutils folder.
In the dosutils folder, doubleclick the icon labelled rawrite.
The rawrite utility will ask you for the disk image source file name. Type d:\images\boot.img (assuming d: is your CD drive) and press Enter.
Rawrite will ask you for the target diskette drive. Type a: (assuming a: is your floppy drive) and press Enter.
When prompted, insert a blank, formatted diskette into your floppy drive and press Enter.
The rawrite utility will return a message telling you whether your disk was created successfully
Insert the e-smith CD into your CD drive.
Click the "Start" button, then "Programs", then the "MS-DOS Prompt" icon.
At the prompt, type d:\dosutils\rawrite (assuming d: is your CD drive) and press Enter.
You will be asked for the disk image source file name. Type d:\images\boot.img (assuming d: is your CD drive) and press Enter.
You will be asked for the target diskette drive. Type a: (assuming a: is your floppy drive) and press Enter.
When prompted, insert a blank, formatted diskette into your floppy drive and press Enter.
The rawrite utility will return a message telling you whether your disk was created successfully.
Under Linux, the commands are:
mount /dev/cdrom /mnt/cdrom
dd if=/mnt/cdrom/images/boot.img of=/dev/fd0 bs=1440k
umount /mnt/cdrom |
Andy McFadden's CD-Recordable FAQ www.fadden.com/cdrfaq
Roxio, Inc. www.roxio.com
Ahead Software www.ahead.de
CeQuadrat www.roxio.de
Golden Hawk Technology www.goldenhawk.com
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Text and no Back-Cover Text. A copy of the GNU Free Documentation License is available on our web site at http://www.e-smith.org/docs/gfdl.html and from the Free Software Foundation at http://www.fsf.org/copyleft/fdl.html.
The e-smith logo and the terms "e-smith" and "i-bay" are trademarks or registered trademarks of e-smith, inc. in the United States and other countries. Linux is a registered trademark of Linus Torvalds. The terms "ssh" and "Secure Shell" are trademarks of SSH Communications Security Corp. All other trademarks are the property of their respective holders.