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How did you manage this?

2001-04-19
2001-08-15
  • Nathan Pitts

    Nathan Pitts - 2001-04-19

    Since I started playing with Beowulf concepts, building a CD-ROM based distribution has always been an interesting proposition for me. I was wondering if you would be willing to share any information on how to start building such a beastie. Anything you are willing to share would be appreciated. (e.g. documentation, reference sites/books to check out.)

    Thanks in advance,

    Irom

     
    • mĺrten sundling

      Hi !

      Ehm ... how did i do it ... well i got tired of those rescue disks :)

      I did a couple of rescue disks a'la 1920 k and so on so forth , then got tired of that too and scratched my head both once and twice ... :)

      Then i read the ' ramdisk ' and net boot  howtos .
      and scratched some more :)

      My Virtual Linux  are quite simple (haha) it is based on a full running Mandrake installation
      copied to a cdrom  .

      The boot sequence and a couple of scripts does the magic , not really that complicated  , but it takes a lot of coffe and late night's before i got a working concept.

      Howitworks:

      1 . a boot image on cd locate a cdrom with the proper cd inserted , then uploads the ' virtual root image : /boot/mand7cd.gz to ram .

      2 . This image (20 mb) contains everything linux needs to have read write access to + some more that it might need it for ( safety ,lazyness )
      like the /etc folder and /bin/cp ,mv,mount,gzip and so on , the rest are also there but linked to a hidden folder described below .

      3 . init starts from the /dev/ram , and the first
      part's of boot are exactly the same as on whatever  Linux box .

      4 . My script findcd try to locate a cd with a linux system on  , if found , it mounts the whole cd in /.virtual_root , where all the links in ram points to .

      5 . another script , vlutil mounts all cdroms , partitons with linux , windows , msdos , ntfs etc
      and create icons for easy handling on the kde desktop  , then it creates a  small swap file if there are a /dev/hda1 and it is vfat .

      6 . normal bootup follows , with kudzu and the rest included with mandrake , somewhat stripped for faster bootup .

      Done , system does not know the difference from a harddrive boot and this approach ........ :)

      Everything works normal , but a little sluggish
      b'cause of  the slower cdrom .

      The speed issue have been veru much better after my latest changes  , i've implemented the cloop filesystem compression by Klaus Knopper knopper.net .

      It makes the  cdrom much faster due to less head movement and a f.a.t in ram ! , ie no swoop swoop swoop sound's from drive etc ...

      This version is not released yet , i'll put it in my next 1.0 release , based on the 8.0 Mandrake .

      Hope this made some things clearer , my English is not the best ... :)

      If you have not downloaded my VL , and would like to  have a look at the system , let med know , i can mail the ramdisks or the scripts so you can see how things work ...

      Cheers , Marten , Sweden .

       

       
    • THOMAS

      THOMAS - 2001-08-15

      Is it possibel to send me the scripts on how you did this, or even the scripts themselves? Also, is there a way to actually have the contents of the CD put into ramdisk memory? I have a 1 GB or ram, so it would fit, and the performance boost would be awsome, since it does not need to keep reading the CD for every function.... it could just access memory.

      My whole thing is to have a complete and working operating system that cannot sustain permanant damge from a hacker or virus.

       

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