How to make a knoppix DVD UNCOMPRESSED

[zorxd]

Hi
I would like to make a DVD version of knoppix (3.6 would be great)

but I would like to use the 4.5 Gb available space to put an uncompressed KNOPPIX file instead of adding more apps

like this there would be no need for a huge ram drive and it will be much faster I guess

Is there an easy way to do this?

It could be the same thing than the hdd-installed version of knoppix since I will use it on only one computer, but it has to work read only (since it's on a DVD) I will do a fat32 partition for storiing my data and configs.

[idonda]

that would be really great!

[ShadowGuy]

I would also like to know how to do this.

[Entropy42]

It would actually likely be slower.

The bottleneck when reading from optical media (CD or DVD) is the transfer rate of the drive, NOT the CPU power needed to decompress the compressed file. (Unless you have a REALLY slow machine.)

i.e. the slowdown induced by compression is nothing compared to the slowdown of having to read the data in an uncompressed form.

[consigliere]

so, how is it?
is it actually slower when using uncompressed file system?
and by the way, how do we make such arrangement,.. that is not to compress the file system?
is it done simply by skipping the make_compressed_fs command?

rgds,
Guido

[sakiZ]

Yes, I've been giving this some thought myself. I have Knoppix 3.7 installed on my HDD right now, so I'm interested in burning the whole thing to a DVD, and if I could make it a bootable live CD that would be even better.

Ideally then, I'd have a bootable DVD with MY current setup. Of course it would also be my backup of my OS.

It should not be that hard.

sakiZ

[Harry Kuhman]

and it will be much faster I guess

My guess is that it will not be faster, and in fact will be slower. You will effectively increase the amount of I/O needed to be done from the disc for any application. I/O is a bottleneck. I think you'll find that it's faster to read the (fewer) compressed sectors and then expand them with a little CPU power than to have the CPU waiting around idle while all of the data comes in from the uncompressed disc.

I saw a pratical application of this over twenty five years ago, back when there were people who still understood that optimizing space and speed is important. A programmer decided to use a form of dynamic huffman encoding to encode text coming from a database for a game, but was a little concerned that the added overhead to decode the huffman encoded text would slow the game. It turned out it sped it up because less disk I/O was used. And this was with a hard drive on a "mainframe" (even then faster than a DVD drive now) and much much less CPU power than you have sitting on your desktop. So unless the klopp decoding code is really really bad, uncompressing the klopp isn't going to be a net gain.

[firebyrd10]

I don't think it would work at all.

The compressed image is in a linux FS wrapper.

The files couldn't have permissions on a iso standard and linux requires that.

[ISoar]

I would like to make a DVD version of knoppix (3.6 would be great)

I've done this. To the nay sayers, it works fine.

Here's what I did:

1) Mount the boot image.
2) Edit the linuxrc
- change cloop to loop
- remove knoppix-ized ash and replace with statically linked busybox with "mount" with loop mounting capability.
3) Make a bunch of symlinks under /static for the busybox components.
4) Unmount the boot image.
5) Uncompress the root ISO image KNOPPIX/KNOPPIX
6) Create a new ISO image - this is the trickiest part IMHO.

I'll put together a web page with more details if there is interest.

[Harry Kuhman]

I've done this. To the nay sayers, it works fine.

You didn't say if it's faster or (as suspected) slower. Give us real numbers please, including:
How long it takes to boot your Knopix CD.
How long it takes to boot your Knoppix DVD (on the same drive).
You CPU type and speed, memory, optical drive make and model.
What speed each the CD and DVD were burnt at (I ask this because a Knoppix CD burnt fast will often take much longer to boot than one burnt slow, due to a high number of retries required during boot).

In addition to booting speeds, you might benchmark the starting of some applications from the optical media, such as GIMP, and tell us how long each takes from first click until ready to run.