KNOPPIX RELOADED – Remastering des Live-Systems Klaus Knopper KNOPPERKNOPPER.NET.NET in Zusammenarbeit mit dem LinuxTag e.V. Stand: 11.02.2004 •First •Prev •Next •Last •Full Screen •Quit c 2003 1 Folie 1 von 17 Summary KNOPPIX (Knopper’s Unix) is a collection of GNU/Linux software designed to run completely from CD without any installation necessary, with automatic hardware recognition and support for many graphics cards, soundcardsKNOPPERKNOPPER and.NET.NET other peripherals. In order to build (or re-build) a live CD installation, there are some technical and non-technical aspects to take into account, which is essential for rebuilding KNOPPIX as a live platform, for running care2x from CD. •First •Prev •Next •Last Folie 1 •Full Screen •Quit c 2003 2 Folie 2 von 17 What is this KNOPPIX, anyways? • Bootable CD/DVD-Rom with • currentmost Linux 2.4 (2.6)-kernel, • compressed filesystem image (ca. 1.8 GB uncom- pressed on one CD, using cloop realtime decom- pression) containingKNOPPERKNOPPER.NET.NET – KDE 3.x as standard desktop, – multimedia players xmms and xine, – productivity applications (i.e. OpenOffice, gimp, scribus, sketch), – internet access through analog modem, ISDN, DSL and (W)LAN, – software for data recovery and network analysis. •First •Prev •Next •Last Folie 2 •Full Screen •Quit c 2003 3 Folie 3 von 17 The Idea KNOPPERKNOPPER.NET.NET Insert CD, do nothing for 3 minutes, start working right away with the ready configured desktop. •First •Prev •Next •Last Folie 3 •Full Screen •Quit c 2003 4 Folie 4 von 17 LICENSE • software collection and KNOPPIX-specific programs, scripts and patches [1]: GNU GENERAL PUBLIC LI- CENSE • individial softwareKNOPPERKNOPPER packages:.NET.NET preferably GPL and other Free software licenses, but also other licenses, as long as they allow ”free redistribution for non- commercial as well as commercial use” • Because of these licenses, the CD can be copied, modified and redistributed by all legal recipients of the CD, even for commercial products. •First •Prev •Next •Last Folie 4 •Full Screen •Quit c 2003 5 Folie 5 von 17 To avoid confusion ... we use slides with a blue background for the basic concept, ... and a greenKNOPPERKNOPPER background.NET.NET for the technical geek stuff that you can safely ignore and don’t have to worry about, if you are not a technical person. Note: We need the green slides again for the workshop this afternoon, btw... •First •Prev •Next •Last Folie 5 •Full Screen •Quit c 2003 6 Folie 6 von 17 The basic content of a KNOPPIX CD KNOPPIX directory cloop KNOPPERKNOPPERBootBoot .NET ImageImage compressed.NET filefile system docs knoppix.sh Software− Talks Software− archivesarchives •First •Prev •Next •Last Folie 6 •Full Screen •Quit c 2003 7 Folie 7 von 17 Remaster uncompressed CD part, steps 1. Copy old CD content to a directory on harddisk. 2. Add your own stuff. KNOPPERKNOPPER.NET.NET 3. Burn this directory to CD, make sure to tell your burn- ing program that KNOPPIX/boot.img is the bootim- age. •First •Prev •Next •Last Folie 7 •Full Screen •Quit c 2003 8 Folie 8 von 17 Remaster uncompressed CD part, example Exchange the Desktop Wallpaper: mount /dev/cdrom /mnt/cdrom cp -a /mnt/cdrom/ /tmp/knoppix_cd chmod -R u+w /tmp/knoppix_cdKNOPPERKNOPPER.NET.NET rm -f /tmp/knoppix_cd/KNOPPIX/boot.cat cp new.jpg /tmp/knoppix_cd/KNOPPIX/background.jpg mkisofs -l -r -J \ -b KNOPPIX/boot.img -c KNOPPIX/boot.cat \ /tmp/knoppix_cd | cdrecord -v -pad - •First •Prev •Next •Last Folie 8 •Full Screen •Quit c 2003 9 Folie 9 von 17 Remaster bootimage, steps 1. Copy kernel with all components necessary to ac- cess a (IDE/SCSI) CD-Rom, to floppy disk (ext2 or vfat). KNOPPERKNOPPER 2. Create and copy initial ramdisk.NET.NET containing /linuxrc startscript, device files in /dev, additional modules to the same floppy disk. 3. Install sysllinux and modify syslinux.cfg accordingly. •First •Prev •Next •Last Folie 9 •Full Screen •Quit c 2003 10 Folie 10 von 17 Remaster bootimage, example mkdosfs -r 16 -f 1 /dev/fd0 mount /dev/fd0 /mnt/floppy cp /boot/vmlinuz /mnt/floppy/ rdev /mnt/floppy/vmlinuz /dev/ram1 dd if=/dev/zero of=miniroot.img bs=3000k count=1 mke2fs -b 1024 -N 8192 -F -q -m 0 miniroot.img mount -t ext2 -o loopKNOPPERKNOPPER miniroot.img.NET.NET /initrd rm -rf /initrd/lost+found cp -a miniroot-template/* /initrd/ chown -R root.root initrd/* umount /initrd gzip -9cv miniroot.img > miniroot.gz cp miniroot.gz syslinux.cfg /mnt/floppy/ umount /mnt/floppy syslinux /dev/fd0 •First •Prev •Next •Last Folie 10 •Full Screen •Quit c 2003 11 Folie 11 von 17 Remaster compressed part, theory Basic procedure: Unpack cloop-Image to harddisk, modify the software installation, create new ISO image and re- compress. Problems: • Data on a CD-RomKNOPPERKNOPPER is always.NET read-only. But some pro- grams require certain files to.NET be modifyable. ☞ create symlinks for those files to the /ramdisk directory and make sure they are copied there prior to program execu- tion (i.e. user home directories, database files etc.). • The cloop blockdevice as well as the iso9660 CD-Rom filesystem are both read-only by design, therefore any changes you make have to be done within a virtual hard- disk installation. •First •Prev •Next •Last Folie 11 •Full Screen •Quit c 2003 12 Folie 12 von 17 Remaster compressed part, example extract_compressed_fs /mnt/cdrom/KNOPPIX/KNOPPIX \ > iso.tmp mount -o loop,ro,dev,suid iso.tmp /mnt/tmp rsync -Hav /mnt/tmp/ /tmp/knoppix_fs (ggf. Hardlinks reparieren...) chroot /tmp/knoppix_fs mount -t tmpfs noneKNOPPERKNOPPER /tmp .NET.NET mount -t proc none /proc apt-get install ... apt-get clean umount /proc ; umount /tmp ˆD mkisofs -pad -l -R -U /tmp/knoppix_fs | \ create_compressed_fs - 65536 > /tmp/KNOPPIX Caution: The last step does require a lot of virtual memory! •First •Prev •Next •Last Folie 12 •Full Screen •Quit c 2003 13 Folie 13 von 17 Post-mortem considerations, for experts It’s not working, what could have gone wrong? • After upgrades or reconfigurations, some leftover, incorrect con- fig files and temporary files may be left, and should be removed prior to creating the cloop image containing the new system. • Running out ofKNOPPER spaceKNOPPER because.NET.NET of a Kernel-Bug: Inodes in hardlinks of iso9660 are not identical. ☞ duplicate space al- location for hardlinks when copied to HD. • Frequent mistake: The filesystem was mounted nosuid,nodev before chroot, no devices will work (including /dev/null). • Again, some files must be relocated into writable (RAM) areas, and may have been missed when upgrading or installing new software. •First •Prev •Next •Last Folie 13 •Full Screen •Quit c 2003 14 Folie 14 von 17 care2x-specific issues • The MySQL database files must be relocated into the /ramdisk before the mysql server can modify them. • Most of the files in the HTML/PHP document tree must also be relocated.KNOPPERKNOPPER.NET.NET • Excessive logging and/or handling of large data files can hog system memory and finally lock up the sys- tem, if not enough RAM is present. • Where to store and load data that needs to be saved over reboot? •First •Prev •Next •Last Folie 14 •Full Screen •Quit c 2003 15 Folie 15 von 17 There may be an easier way... During boot, KNOPPIX executes a shell script called knoppix.sh from the KNOPPIX directory if present. You could, in theory, install, configure, run and shut- down all third-partyKNOPPERKNOPPER software from there, using space in the ramdisk for all writable data..NET.NET Drawback: Needs some shell magic, and probably needs more memory than installing the software onto the compressed filesystem part would. •First •Prev •Next •Last Folie 15 •Full Screen •Quit c 2003 16 Folie 16 von 17 Links (1) [1] http://www.knopper.net/knoppix/sources/ KNOPPIX Source Repository [2] KNOPPIX Info / Forum / Contakt/ Developers List: http://www.knoppix.de/KNOPPERKNOPPER.NET http://www.linuxtag.org/forum/ .NET [email protected] [email protected] •First •Prev •Next •Last Folie 16 •Full Screen •Quit c 2003 17 Folie 17 von 17.