knoppix 7.4.2 persistence

[rspiteri]

@rajibando... I appreciate your help really but unfortunately as I told you, your solution is not valid in my case... I cannot just create partitions on others' PCs. Also I prefer to have a file (.img) rather than a partition. It is more portable in my opinion.

@ Werner P. Schulz... I read your post over and over again going through all the links... I even tried to patch minirt.gz with no luck... Can you please guide to what scripts do I need to modify and where please?

I thank you both for your patience.

I really like Knoppix and would like to learn more about this distro.

[Werner P. Schulz]

The interesting part of the script "flash-knoppix2" → "If we don't already have an overlay, ask to create one"

How Knoppix interprets the config files (knoppix-data.inf, knoppix-data.aes or knoppix-data.img) during boot, you can see within the "init"-file of the minirt.gz → function mountdata()

Read and analyze the source code.

If you want another behaviour of Knoppix and his overlay you have to change these two scripts, insert your own code and remaster Knoppix.

[rajibando]

...I cannot just create partitions on others' PCs,,,

You haven't read and understood.

[rspiteri]

Hi,

I managed to accomplish what I wanted.

Modified mountdata() to check for a new boot parameter which I called overlay and now when you type:

knoppix overlay=/dev/sda1

Init will mount /dev/sda1/knoppix-data.img to KNOPPIX-DATA

I need to update it to cater for aes as well

Thanks for all your help

[rajibando]

Now it is your turn to elaborately explain via a post about the steps you took to accomplish your target and where you were going wrong, including the support you obtained from various threads.

You know, freedom comes at a huge price which some of us don't like to pay, but take freedom for granted. We forget that some of our predecessors fought relentlessly for those freedoms.

Intentionally, we don't spoon-feed you because we wish to keep your choices free. Sometimes, we fail to get the message across. And the seekers turn highly abusive - they usually don't wish to own up responsibility and ask the right questions. Usually, they want to be spoon-fed.

I have a difficulty with reading, I am visual, so Linux is difficult for people like me, while people who read relentlessly find it cakewalk. I overcame this difficulty by skimming through the text, trying to pick up things that I require. I don't complain that people don't understand. Why should they understand? It is my problem and I have to solve it. What is my mind (brain) for, if it can't find a way?!

We give up easily and say we don't have time to read or experiment. As if others are in lesser responsible positions!

I have found that if I ask the right questions there are people who would answer my query. And sitting still like in meditation helps a lot. Your subconscious mind provides you answers but you have to be really calm and attentive to listen.

Anyway, keep learning, and remember the suggestions I had earlier given you.

[rspiteri]

Basically I have followed the links and comments you both supplied and came up with the following solution:

1. Decompress minirt.gz
2. Open init with vim.
3. At the start of mountdata(), use checkbootparam() to check for if the overlay parameter exists
4. If yes, read its value and mount the image as loop on KNOPPIX-DATA using trymount(), outputting a valid message at boot (optional)

Basically the code to mount the overlay image is already there in mountdata(), I just reused it for my purpose.

Now obviously I can tweak init to search if the overlay exists before mounting it, but for now I am satisfied with the output since I managed to do what I had in mind.

Then it is

[rajibando]

Thank you for posting your experience.

But why do you have to take the hard way? Editing minirt.gz.

You could have :

(1) been patient
(2) Booted to the laptop owner's system normally.
(3) Copied your pendrive's boot and KNOPPIX folders, renamed your pendrive's KNOPPIX binary to KNOPPIX000.
(4) Booted from your pendrive, let your syslinux search and find the HDD's KNOPPIX binary and knoppix-data.inf and boot from there.
(5) You could also have used knoppix-data.img had you so chosen.

Matter ends.

There is a phrase called Occham's razor. You are a programmer, so also try to find simple solutions

It is not for a reason that Windows has been DBD, i.e., defective by design

Anyway, best wishes with your professional work. Bye!

[Werner P. Schulz]

knoppix overlay=/dev/sda1

3. At the start of mountdata(), use checkbootparam() to check for if the overlay parameter exists

Your way to use a own cheatcode and test for it within a modified init (of minirt.gz) is a simple and nice solution.

[rajibando]

...simple and nice solution...

But rspiteri is not booting knoppix in his system!
He wants to boot knoppix from his clients' systems, and the clients may not allow by default rspiteri's saving the KNOPPIX image in the HDD of his lap(desk)top's first partition. Then his edited minirt.gz will fail, and his pendrive syslinux will use the default method to search and find out the KNOPPIX image from the HDD, I am not aware if the modified init shall fail.
In that case, it is worthwhile to let the minirt.gz alone and let syslinux do what it does best.
Anyway his approach is not general.
Else, please advise.

[rspiteri]

Your way to use a own cheatcode and test for it within a modified init (of minirt.gz) is a simple and nice solution.

Thanks for the feedback Werner P. Schulz, I appreciate...

@rajibando, perhaps you did not understand me well then. let me explain better...

1. I boot knoppix from my pendrive on every machine and NOT from the client's machine. That would not make sense since I need 4GB on disk on every machine then.
2. However I do not want to store all the different clients' modifications (keyboard settings, wifi settings etc) on my pendrive.
3. Therefore I create a knoppix-data.img file on each client's machine.
4. Finally I specify overlay=/dev/sda1 (where sda1 refers to the partition where the overlay file (knoppix-data.img) is found. (overlay is the new boot parameter I configured init to look for)
5. That's it. Like this, if I need to save few settings or make minor modifications for the future, I just create a 500MB overlay file and save all changes there.
6. If I do not want to save any settings or modifications on the client's machine, I just omit the overlay boot parameter and knoppix will boot normally in "read only" mode. My edited minirt.gz does not search for an img file on the client's machine unless the boot parameter is specified.

The solution you proposed also works but is very expensive in terms of the client's disk space.