The CD-Rchive Handbook: Making an Image

Contents

## Making an Image

### Step 1. Pre-mastering data

The best strategy I have found for making CDs, is to actually create the directory structure you require on the CD, on your hard drive. It is possible to graft data to new directories in the image file, but it leaves problems with the permissions and ownership of the directories and long cumbersome commandlines.
Given the price of hard drives, if you can afford a CD Writer there is no reason you should not have a hard drive large enough to set aside a partition or directory for mastering data.
You do not have to duplicate all the data already present on your machine in this data mastering directory.
You can use symbolic links, so long as you are certain that you will not end up including all sorts of data you had not intended to.
It may be beneficial however as part of an overall archiving / backup policy to mirror critical data in other directories and preferably onto other physical drives. It certainly increases the safety of valuable data against mechanical failure.
If this mirroring is done into your data mastering partition then you have a neat solution which meets both needs. This is what I do.
IMPORTANT - 08062001 - latest versions of mkisofs have deprecated the -a switch which equates to setting the 'Include all Files' checkbox on the 'Image' tabpage of CD-Rchive.
Versions from 1.2.1 no longer include this automatically in the preset selections
If you get mkisofs errors regarding use of -a switch, turn this selection off.
It remains a valid switch for older verions of mkisofs, to ensure inclusion of backup files etc.
There is a check box in the Image Settings group on the Image tab page which allows the following of symbolic links. Used with care, this can reduce the amount of data required to physically present in the mastering directory drastically.
Create a symbolic link with:-
ln -snf /target /link
or use Midnight Commander or some other decent file manager to create the necessary link.
The danger of symbolic links is of recursion through following further links in the directories you have linked to. You could include huge amounts of data you did not intend archiving.
The associated danger of infinate looping, where a link leads to another link which points back to the first link should not occur as I have only used the safer mkhybrid -f switch which does not suppress loop checks.
The documentation for mkhybrid seems to suggest that you cannot link to directories with the -f switch. Experimenting I have found you can link to mounted block devices if you like, mkhybrid will include the contents in the image file.
So down to a practical example.
On my 3rd IDE hard drive, on which I have a formatted Linux partition, mounted as /L: (just makes it easier for me to remember what is on each drive if I use the DOS assignment letter, since I run several operating systems on my machine) I create a directory called /L:/cdimage
This directory is the root directory for the image file.
In this directory are 2 sub-directories and 3 sym links ( each pointing to a directory on my 2nd IDE hard drive, which is my Linux drive.)
I have a copy of /etc called suprisingly enough, /etc!
There is one of /root/prog/versions called versions, which is my archive directory for programming code.
The sym links are to directories which contain no sym links themselves, being collections of downloaded rpm's, source etc, which I want to have an up to date archive of so I can delete the files on hard drive if necessary.
When I make the image I specify the path /L:/cdimage in the Source Paths combo box on the Source tab page, and what I get is an image with a directory structure like:-
.
..
/etc
/versions
/packages
/downloads
/uploads

### Step 2. Checking image files

Of primary importance on this subject is IF YOU CAN'T MOUNT AND VIEW AN IMAGE, DON'T WRITE IT TO DISC
The major exception is when making a multi session CD
So whenever you make an image, mount it and view its contents. If it won't mount or part of it cannot be viewed or appears incomplete ditch it and start again. Remember that you can't open files with the file browser.
If you are not sharing data on CD between Linux or other Unix variants and DOS or Windows variants, use Rock Ridge option but not Joliet. It seems to increase the reliabilty of the images made, don't ask me why.
Writing Data Image(s) to CD