Device mapper custom made LiveDVD

[lilsirecho]

Utilizing device mapper technique permits the generation of a LIVEDVD with full 4.4GB of program material that boots from the normal CD /KNOPPIX file.

The normal CD file may or may not be enhanced with more program material with this method. Usual re-master techniques will allow 2GB to be provided by re-master procedures within the KNOPPIX/KNOPPIX file. This is too large for a CD burn but is device-mapped with this technique to permit it to be burned to a DVD disc.

The technique involves splitting the KNOPPIX CD.iso into a prefix.iso and a suffix. The prefix.iso contains the boot params and the suffix is the KNOPPIX/KNOPPIX file. Each of these can be customized to provide 2GB of programs and then be joined in concatenation before burning to DVD.

To accomplish this result requires replacing the minirt.gz in the boot folder with a new minirt.gz provided by Belyi at his website(see DVD forum for url).

The technique I used to produce a LIVEDVD is as follows;

Copy CD KNOPPIX v3.8.2.iso to new folder...NEWIMAGE....Open.....NEWIMAGE
Open /boot/isolinx/ and delete minirt.gz from NEWIMAGE.
Install the new minirt.gz into NEWIMAGE (previously obtained from Belyi url).
Open KNOPPIX directory in NEWIMAGE
Move /KNOPPIX file to desktop.
Open /boot/isolinux and select ...isolinux.config...to permit editing. Edit the config file to your desired arrangement and cheatcodes..SAVE and exit.
Install in the KNOPPIX directory in NEWIMAGE the added program material in appropriately named folders. I made two folders of material, KNOPPIXU (the uncompressed KNOPPIX 1.7GB) and a CMG folder containing several CMG files (compressed image files, cramfs compressed)..(I had previously installed 2.5GB of video in this directory and burned to disc with this method successfully).
The NEWIMAGE folder is now prepared for mkisofs routine:

mkisofs -pad -l -r -v -V "KNOPPIX" -no-emul-boot -boot-load-size 4 -boot-info-table -b boot/isolinux/isolinux.bin -c boot/isolinux/boot.cat -hide-rr-moved -o KNOPPIX-prefix.iso NEWIMAGE .....NOTE: I had to delete the -J option when running mkisofs..dunno why!

The concatenate command is then performed;
cat KNOPPIX-prefix.iso /root/Desktop/KNOPPIX > KNOPPIX-final.iso.... This command device-maps the /KNOPPIX file and it no longer is visible when examining the contents of the KNOPPIX directory !

The KNOPPIX-final.iso is now prepared for burning to DVD+RW disc(recommended for experiments).

The DVD boots to a normal KDE desktop with persistent home and config. To obtain access to the new material in the prefix.iso, select HOME/devices, cdrom(the booted DVD reader which is a cdrom with DVD rom reader in my system). This may be named...devicemappercdromcdrom...which it is named in my system. Opening this DVD .iso gives access to the KNOPPIX directory. Select the desired folder for use from the KNOPPIX directory.

I have run CMG files from this Directory and as well games from the uncompressed KNOPPIXU folder.

I invite comments concerning the methods of applying the uncompressed KNOPPIX as well as advice on what compressed file systems other than the limited cramfs might be utilized in the prefix.iso. Cloop might be applicable up to 2GB.

The method I describe should permit the normal KNOPPIX CD /KNOPPIX/KNOPPIX file to remain unchanged and all the changes to appear in the prefix which allows.... 4.4GB minus 0.7GB = 3.7GB....to be added to the prefix alone. If this material is compressed 50%, the total uncompressed capability (with the basic 2GB in KNOPPIX) equals 9.4GB. It takes a lot of time to generate that much compressed program material!!!!

I am not expert enough to know what to do with the uncompressed KNOPPIX file I have on DVD which is in the presence of the cloop compressed system of the identical material!

I invite suggestions on that point and also what compression could be used on material in the prefix other than cloop which would also read "on-the-fly".(squashfs?)

The UNIONFS appears in the normal KNOPPIX format. I do not know where it is in the uncompressed KNOPPIX directory (perhaps not there any more).

This was just an experiment with KNOPPIX customizing, hopefully useful.

[lilsirecho]

A further note regarding the system as described for device-mapped KNOPPIX.

The KNOPPIX CD designed by Klaus Knopper was optimized for booting by arranging the material to be loaded in sequences that reduced boot time.

If the user re-masters the probability is it will increase the boot time for the re-mastered CD/DVD.

If one uses the original format (keep the CD KNOPPIX/KNOPPIX file intact) the boot time will be optimized.

It would be possible to add uncompressed data to the /KNOPPIX file to provide 2GB of read-only material, say, some video files. This would keep the boot time optimized. The added file(s) would be addends and not cloop related, thus should not impact boot time AFAIK.

The material to be inserted into the prefix as compressed data probably cannot be cloop-related unless it performs its decompression after boot.

The UNIONFS is still operative in the normal boot params with the device-mapped system. Should a system be instituted within the prefix options to permit compressed material (in addition to CMG) , the possibility exists to have four or more useable modes in a LIVEDVD (including uncompressed).

Experiments continue.....

[lilsirecho]

Thanks for your trial.

The source code of fs_wrapper is opened at the following URL.
http://unit.aist.go.jp/itri/knoppix/...er.0.36.tar.gz
The source code to make " split-and-compressed block files" is also opened.
http://unit.aist.go.jp/itri/knoppix/...d5files.tar.gz

They aren't well organized, because they are under construction. Please use them on your risk and have fun!
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The above URL may be useful in providing "split and compressed files" to enable more than one "cloop" file to be included in a DVD burn. It is provided by a Japanese source and is used to produce "Fuse KNOPPIX" as described in IDEAS forum.

[lilsirecho]

Info regarding the release of KNOPPIX 4.0 indicates a DVD version of 9GB uncompressed will be released on Wednesday at Linux Tag.

Discussion of the details occurs in the NEWS forum which indicates limitations may exist for FAT file system computers which limit files to 4GB.

If the cloop compression system were just doubled, instead of 2GB...have 4GB, the system might fit with the DVD.

The max data on a DVD is 4.4GB which certainly should produce 9GB uncompressed.

Whether one can use the .iso in his system or not, this is a big, big, big KNOPPIX release!!!!!