• ISOhybrid conversion: Starting with version 3.8x of the Syslinux bootloader an ISO image can be prepared to be a valid hard disk image. Isolinux will boot this image in any case. There is one drawback however: A USB thumbdrive with this ISO image does not contain a writable filesystem anymore. Current LessLinux builds include a conversion routine: If sufficient RAM is found, the complete content of the ISO filessystem is copied to RAM during startup, the thumbdrive is reformatted as FAT32 and a Syslinux bootloader is written.

  To test this feature, use dd to copy the ISO to the thumbdrive: dd if=lesslinux.iso of=/dev/sdx. On Windows rename the ISO to .img and use Win32ImageWriter to perform this task.

• Start as Xen domU: With pvops Vanilla kernels getting mature it is possible to boot the same kernel on bare hardware and as Xen domU on the hypervisor. With small changes to the kernel configuration and the startup scripts (to search on Xens harddisks xvda and to open the console hvc0) LessLinux now boots on Xen. The practical usage of this feature will be for development and debugging, but it also offers the possibillity to offer lightweight live distributions as maintenance and rescue systems for hosting environments.

  To boot on Xen you must convert the initramfs files of the Vanilla Kernel 2.6.35.4 to a format that the domU loader understands — basically converting the multiple compressed cpio archives from /boot/isolinux to a single one:

  cat devs.img initram.img i2635vn.img | gunzip -c | gzip -c > initrd.img

  Then use this configuration file to fire up the domU. On pressing the Return key on hvc0 you get a simple shell where you can use ifconfig to determine the IP adress. Then use VNC to connect to the desktop of your LessLinux-domU.

  

Other new features:

• Kernel: 2.6.34.6 is default, 2.6.35.4 is optional
• Firefox: By running /opt/firefox40/lib/firefox/firefox you can start Firefox 4.0b4 with WebM support
• VLC: upgraded to 1.1.4
• Thunderbird: upgraded to 3.1.2, Enigmail and Lighning included

Known bugs:

• USB installation from the boot menu might not work, use ISOhybrid as mentioned above
• Sound will not work when booting Kernel 2.6.35.4
• Shutdown is blind due to some KMS issues
• Truecrypt manually load module fuse before running Truecrypt

Grab it here:

• Download from lesslinux.org lesslinux-search-and-rescue-uluru-20100903-134327.iso

Well it can be easier. Just configure your DSL router to forward inbound traffic on port 5500 to your desktop machine and get a nice DynDNS hostname. Then remaster any LessLinux Search and Rescue CD to include one boot entry that does not disable earlynet and add the cheatcode

        xvnc=|reverse|1280x800|24|my.dyndns.name|

In case of emergency tell your grandma to boot the CD with the respective entry. The earlynet script requests an IP address on all wired interfaces and instead of starting a local Xserver Xvnc is started and a reverse connection to your host is made where a listening VNC viewer must be running.

There is one drawback: the data is transmitted unencrypted, which might be an issue with sensitive data. You might however use this first VNC connection to build up a SSH tunnel between two hosts.

The background of this feature: I got some customers quite far away from here. With this cheatcode I can help them no matter where they are – no special configuration of their router required. This feature also will work over WLAN soon. I just introduced some cheatcodes to attach to a wireless network while startup. Those are not tested yet, so please be patient for a few more days.

Should work in all builds higher than 20100701-000000.

        nfs=192.168.1.1:/dir/containing/iso

In this case, the NFS share is mounted read only (and no locking takes place), then all ISO files down to depth 2 are searched, loop back mounted and scanned for the proper version.txt. If the system is found, the settings for toram=value take place. In reasonable fast networks you should keep this threshold low, then the start of a program via network is quick, on networks with bad latencies you might set a low threshold to copy the entire system to RAM during startup.

You might download the ISO and the sources here:

• lesslinux-search-and-rescue-uluru-20100726-105414.iso
• lesslinux-search-and-rescue-uluru-20100726-105414-buildscripts.tar.bz2

To build yourself follow the instructions in those two articles: Build stage 01 and 02 and Build stage03.

LessLinux ist ein offenes System. Mir liegt viel daran, dass eine breite Masse von Nutzern aller “Erfahrungslevel” mit den LessLinux-Systemen arbeitet, Kritik übt und Verbesserungsvorschläge beisteuert. Mir geht es dabei besonders um Feedback “normaler Nutzer”, denn dieses ist unheimlich wichtig, wenn es darum geht, ein wirklich benutzerfreundliches System auf die Beine zu stellen.

Trouble Ticket System

Seit einigen Wochen steht ein Trouble Ticket System bereit, schreiben Sie einfach eine Email an support@mattiasschlenker.de. Sie erhalten dann eine automatisch generierte Mail mit Ihrer Ticket-ID und schließlich Antwort von uns. Wir versuchen Support-Anfragen zeitnah zu beantworten, aber es kann vorkommen, dass eine Antwort einige Tage auf sich warten lässt – insbesondere dann wenn gerade an einem in Ihrer Mail angesprochenen Problem gearbeitet wird.

Support für Leser von Zeitschriften

Die Verträge mit Computerzeitschriften sehen in der Regel einen Support für einen begrenzten Zeitraum (in der Regel bis ca. 2 Monate nach Ende des Verkaufszeitraumes des Heftes) vor. Der Support erfolgt dabei üblicherweise auf zwei Ebenen:

1. Sie schreiben an die im Heft angegebene Email-Adresse für Lesersupport. Bei häufig ähnlich gestellten Fragen antworten Mitarbeiter, die von uns eingewiesen wurden.
2. Fragen, die die Redaktion nicht beantworten kann, leitet sie uns weiter, wir kümmern uns dann via Trouble Ticket System darum.

Ist das betreffende Heft schon etwas älter, können Sie den oben beschriebenen Weg direkt über das Trouble Ticket System nehmen. Wir werden auch nach Ende des offiziellen Supportzeitraumes eines Heftes keine Anfragen zurückweisen, bitten aber den folgenden Punkt zu beachten.

Wer bezahlt für den Support?

Tatsächlich finanziell gedeckt ist nur bei Zeitschriftenbeilagen der relativ kurze Zeitraum bis maximal zwei Monate nach Verkaufsende des betreffenden Heftes. Wir werden danach keine Supportanfragen abweisen – schon aus dem einfachen Grund, dass viele Supportanfragen wertvolle Hinweise für die Weiterentwicklung des Systems geben. Es gelten die oben genannten Einschränkungen hinsichtlich Antwortgeschwindigkeit.

Sollten Sie mit dem Support zufrieden sein oder einfach einen Beitrag zur Entwicklung von LessLinux leisten wollen, dürfen Sie das gerne tun. Allerdings sind PayPal-Buttons nicht unser Favorit, wir bevorzugen den klassischen Weg von Rechnung und Überweisung. Der dafür erforderliche Aufwand lohnt sich bei Beträgen ab 5 Euro netto (5,95 Euro brutto). Sollten Sie Support und Entwicklung unterstützen wollen, schicken Sie einfach eine Email mit Rechnungsadresse und Betrag an ms@mattiasschlenker.de, Sie erhalten dann postwendend eine Rechnung im PDF-Format oder auf Wunsch eine Rechnung per “gelber Post” (bitte dazuschreiben).

Support und Auftragsentwicklung für Geschäftskunden

LessLinux hat ein recht großes Potential als Notfall- und Deploymentsystem in Firmennetzen. So kann bereits heute LessLinux aus dem Netz gebootet und vom Administratordesktop aus per VNC (auch per SSH getunnelt) “ferngesteuert” werden. Mit den enthaltenen Tools lassen sich so aus der Ferne Datenrettungen oder das Deployment von Windows-Images durchführen. Von hier ist es nur ein kleiner Schritt zu angepassten Images, mit denen beispielsweise automatisches Deployment möglich ist.

Fragen Sie einfach nach, ob ein bestimmtes Feature bereits vorhanden ist oder wie groß der Aufwand wäre, dieses zu implementieren. Bei aufwendiger zu implementierenden Features kann der Aufwand auf mehrere Interessenten umgelegt werden. Die Abrechnung erfolgt in diesem Fall nach vorher vereinbartem Kostenvoranschlag, auf der Rechnung werden Entwicklungsstunden ausgewiesen, selbstverständlich ist die MwSt. ausweisbar und die Rechnung im Regelfall als Geschäftsausgabe absetzbar. Bei Interesse kontaktieren Sie bitte Mattias Schlenker per Email an ms@mattiasschlenker.de.

• lesslinux-search-and-rescue-uluru-20100528-114807.iso

Currently for netbooting a DHCP and PXE server are required, a HTTP daemon should be present, although it is possible to load the ISO directly from download.lesslinux.org. For now the ISO is completely stored in volatile memory — future versions will probably also allow NFS access. To load an ISO via HTTP just one additional parameter is necessary:

     wgetiso=http://host/path/lesslinux.iso

Of course you can use the download link above for your first tests, but please remember to change it to a local HTTP server as soon as your setup works to keep traffic at an acceptable level. Now you may combine the information from the last post with a PXE server to build a netbooting, remote accessible version of “LessLinux Search and Rescue”. Take a look at the documentation of PXELINUX and you determine when which system boots via network.

1. Setup a PXE boot environment

German speaking readers might head here, where I describe the setup of a DHCP-PXE-TFTP-boot-chain. Build the setup and test with a simple OS like memtest to confirm that it works flawlessly.

2. Copy the boot files from the LessLinux CD

Our example expects the contents of /boot/isolinux in /llsar within the TFTP root directory, so just use rsync or cp to copy all files contained in this directory.

3. Setup the boot loader

Use isolinux.cfg as a template for your entry in pxelinux.cfg/default. Make sure that earlynet is not contained in the services to skip (upcoming releses will skip this service since it waits for about 15 seconds for DHCP configuration). Then decide which options you want to add. I ended up with three entries. One for a local desktop, two to encrypted and unencrypted VNC access:

LABEL llsar
MENU LABEL LessLinux Search and Rescue LOCAL
KERNEL /llsar/l2634vn
APPEND initrd=/llsar/devs.img,/llsar/initram.img,/llsar/i2634vn.img ramdisk_size=100000 vga=788
    ultraquiet=1 security=none skipcheck=1 quiet lang=de ejectonumass=1
    skipservices=|installer|xconfgui|firewall|mountdrives| hwid=unknown laxsudo=1
    wgetiso=http://192.168.1.56/ll.iso
TEXT HELP
  Start LessLinux Search and Rescue with local desktop.
ENDTEXT

LABEL llsarvnc
MENU LABEL LessLinux Search and Rescue VNC
KERNEL /llsar/l2634vn
APPEND initrd=/llsar/devs.img,/llsar/initram.img,/llsar/i2634vn.img ramdisk_size=100000 vga=788
    ultraquiet=1 security=none skipcheck=1 quiet lang=de ejectonumass=1
    skipservices=|installer|xconfgui|firewall|mountdrives|runtimeconf| hwid=unknown laxsudo=1
    wgetiso=http://192.168.1.56/ll.iso xvnc=|remote|1280x800|24|
TEXT HELP
  Start LessLinux Search and Rescue with insecure VNC desktop.
ENDTEXT

LABEL llsarvnc
MENU LABEL LessLinux Search and Rescue SSH
KERNEL /llsar/l2634vn
APPEND initrd=/llsar/devs.img,/llsar/initram.img,/llsar/i2634vn.img ramdisk_size=100000 vga=788
    ultraquiet=1 security=none skipcheck=1 quiet lang=de ejectonumass=1
    skipservices=|installer|xconfgui|firewall|mountdrives|runtimeconf| hwid=unknown laxsudo=1
    wgetiso=http://192.168.1.56/ll.iso xvnc=|local|1280x800|24|
    rootpwhash=$1$ILXt/Dc3$DmYp.51WCDNjGuTL90eju/
TEXT HELP
  Start LessLinux Search and Rescue with VNC-over-SSH desktop.
  (SSH password is "test", please change!)
ENDTEXT

Please note that the indented lines after APPEND are part of the append parameter line. I had to break the lines to prevent the formatting from exploding. With this setup you can try the full netboot of “LessLinux Search and Rescue”.

• Booting the kernel and initramfs with PXE and loading the system ISO with wget by http or ftp
• Starting the desktop with Xvnc instead a local X server

Currently both functions just work with a wired network interface. This post covers VNC access, I will write on PXE booting later.

To test VNC access, download the latest build:

• lesslinux-search-and-rescue-uluru-20100527-082411.iso

…or build it yourself according to the last two articles withe those buildscripts and overlays (in this case the extra switch -u for unstable is necessary):

• lesslinux-search-and-rescue-uluru-20100527-082411-buildscripts.tar.bz2
• lesslinux-search-and-rescue-uluru-20100527-082411-overlays-neutral.tar.bz2

Doing it the easy way

In trusted networks, you may start Xvnc on the external interface, this means VNC access is granted without password. Just press the Tab key in the boot menu and add

        xvnc=|remote|1280x800|24|

The first value tells Xvnc to bind to the external interface, the second is the screen resolution to use (any value is accepted here), and the third parameter is the color depth. On congested networks you might reduce the depth to 16. It also makes sense to add runtimeconf to the list skipservices. When finished booting, you can connect on port 5900.

Doing it the secure way

Specifying

        xvnc=|local|1280x800|24|

tells Xvnc to bind to 127.0.0.1. So no external connections are allowed. To access, you must tunnel port 5900 over SSH. To make this possible, first remove ssh and roothash from the list skipservices, then add a roothash by specifying:

        rootpwhash=$1$ILXt/Dc3$DmYp.51WCDNjGuTL90eju/

This is the MD5 hash for the simple password test. I created this Hash with the command openssl passwd -1, Apaches htpasswd might also work. Then after the system is fully booted, you can first connect with SSH and use -L to forward :

        ssh -L 5900:localhost:5900 root@192.168.1.23

Now VNC is available on port 5900 on you local machine, simply connect this way:

        vncviewer localhost:0

The current build also is the first one to use kernel 2.6.34 and it introduces libraries from Gnome 2.30. So please test and give me feedback!

Start with the overlay that has to be unpacked directly in /mnt/archiv/LessLinux:

    cd /mnt/archiv/LessLinux
    wget http://download.lesslinux.org/overlays/lesslinux-search-and-rescue-uluru-20100507-000000-overlays-neutral.tar.bz2
    tar xvjf lesslinux-search-and-rescue-uluru-20100507-000000-overlays-neutral.tar.bz2

Now change directory to /mnt/archiv/LessLinux/llbuilder/lesslinux-builder and run builder.rb:

    cd /mnt/archiv/LessLinux/llbuilder/lesslinux-builder
    ruby builder.rb -n -s 1,2,bootconf \
        -p config/pkglist_neutral_rescue.txt \
        -c config/general_neutral_rescue.xml \
        -b config/branding_neutral_rescue.xml \
        -k config/kernels_rescue.xml

The parameters are as follows:

• -p use a certain pkg_list, this is a simple text file containing one package per line
• -c use a certain config file, this contains paths and assumptions on the layout of the final system (for example how kernel modules are loaded)
• -b use a certain branding, this would be the first file to customize when building your own version of LessLinux
• -k use a certain kernel configuration, you would modify this file when using different kernels

After the build is done, take a look at the stage03 directory, you will find the finished ISO image here:

    # ls -lah /mnt/archiv/LessLinux/llbuild/stage03
    total 391M
    drwxr-xr-x   7 root root 4.0K 2010-05-07 09:33 .
    drwxr-xr-x   5 root root 4.0K 2010-05-07 08:45 ..
    drwxr-xr-x 300 root root  12K 2010-05-07 09:13 build
    drwxr-xr-x   6 root root 4.0K 2010-04-13 12:50 cdmaster
    drwxr-xr-x   4 root root 4.0K 2010-05-07 09:32 cpio-2633vn
    -rw-r--r--   1 root root  18M 2010-05-07 09:32 cpio-2633vn.gz
    drwxr-xr-x  14 root root 4.0K 2009-10-13 17:25 initramfs
    -rw-r--r--   1 root root 7.6M 2010-05-07 09:32 initramfs.gz
    -rw-r--r--   1 root root 365M 2010-05-07 09:33 lesslinux-search-and-rescue-uluru-20100507-084527.iso
    drwxr-xr-x   9 root root 4.0K 2010-05-07 09:32 squash

You might now dd the ISO to an USB stick to create a bootable device without having to burn:

    dd if=lesslinux-search-and-rescue-uluru-timestamp.iso of=/dev/sdx

That’s it for today, in the next days we will add some more software and change the branding of your own build.

Currently the only supported build environment is VMware, this means you must have either VMware Workstation, VMware Player (Win, Linux) or VMware Fusion (Mac OS X) installed. Player is sufficient, since the build environments are considered as some kind of “disposable environment”. Note that the VMware image expands to up to 80GB, to prevent fragmentation and reach best performance you might want to put it on a separate partition.

You might download the VMware image from: http://download.lesslinux.org/builder/vmware-images/. This howto uses the file LessLinux_Builder_20100504_Ubuntu_910.zip. Unpack it and run it by calling ubuntu.vmx. As soon as the virtualized Ubuntu is fully started up, you can log in as root with an empty password. Set the password with the command passwd (note that at this point an english keyboard is active – for german readers this means “z” and “y” are swapped!). Log out and log in again using ssh.

Building stage01

The build of stage01 closely ressembles this chapter of the Linux From Scratch handbook. We basically build a set of tools under /tools that are later used to build the system itself in the second stage. Since just glibc, the toolchain and some of the basic Linux utilities are build, this step takes usually one and a half to four hours.

When logged in, change your directory to /mnt/archiv/LessLinux, there create three new subdirectories:

    cd /mnt/archiv/LessLinux
    mkdir llbuild llbuilder src

Change to llbuilder and download and unpack the source/script tarball of the release you intend to build:

    cd /mnt/archiv/LessLinux/llbuilder
    wget http://download.lesslinux.org/src/lesslinux-search-and-rescue-uluru-20100507-000000-buildscripts.tar.bz2
    tar xvjf lesslinux-search-and-rescue-uluru-20100507-000000-buildscripts.tar.bz2

This results in a new directory lesslinux-builder, change to this directory and start building of the first stage:

    cd /mnt/archiv/LessLinux/llbuilder/lesslinux-builder
    ruby builder.rb -n -s 2,3

This command tells the script builder.rb to run no tests and to skip the second stage (build of software within the chroot) as well as the third stage (assembly of the live system). When finished a backup of the resulting chroot environment as well as of the database at this point will be made — we will refer to those later.

Building stage02

In stage02 all the software defined in the XML build definitions in /mnt/archiv/LessLinux/llbuilder/lesslinux-builder/scripts/stage02 will be built. Since two kernels, Firefox, Thunderbird and lots of “expensive” C++-stuff are built you should calculate between one and four days for this build:

    cd /mnt/archiv/LessLinux/llbuilder/lesslinux-builder
    ruby builder.rb -n -s 1,3

It is also possible to specify breakpoints. This means to interrupt the build procedure after a certain package is being built. This feature is usually intended to build package by package after large changes to the package versions or build parameters. For example to stop right after xz (before building the kernels):

    ruby builder.rb -n -s 1,3 -d xz

You might want to take a look at the XML files located in scripts/stage02 to determine where to take breaks.

That’s it. As soon as you (and my stage02) build is complete, I will tell you how to assemble an actual working live system in stage03!

Notes

• If a FTP download hangs, you might interrupt it by pressing Ctrl+C, then the download should try again via HTTP
• If the build cannot start due to missing files you might either remove the stage02 build definition that uses the missing file or you manually download the file
• VMware will suspend if you work on a nearly full file system, to prevent a dropped SSH connection from interrupting a build, use screen
• If you started with lesslinux-search-and-rescue-uluru-20100413-192604-buildscripts.tar.bz2 the build fails at gnutls, in this case unpack lesslinux-search-and-rescue-uluru-20100507-000000-buildscripts.tar.bz2 in /mnt/archiv/LessLinux/llbuilder (this will replace scripts/stage02/5282_gnutls.xml and scripts/pkg_content/gnutls-2.8.6.xml), then run again builder.rb, the build will now continue and finish.

• Computer Bild Russia had the LessLinux based Sicher Surfen as Cover Disc in January
• Computer Hoi did same same
• Komputer Swiat Poland will follow in the next days
• Computer Bild Germany had a “Banking CD” with a very strict SMACK ruleset in January
• Data Becker uses a LessLinux based burning tool on the cover CDs of Linux Intern

In the meanwhile I am busy upgrading, including new software and opening the development. If you want to help, please grab one of the test builds from download.lesslinux.org/testing/, run it and tell me, what attracts you and what doesn’t fit your needs.

If the testbuild should not start in you language, press “Tab” in the boot menu and change lang=de to lang=en (or ru, pl or es — other languages are just partially supported.

Features include:

• Usage of SMACK to allow internet access for certain programs only
• Kernel hardened with PaX to limit the risk of buffer overflows
• Password protection for the access to disks and USB sticks
• Installable on USB thumb drives with encrypted container for the home file system
• Easily updatebale when installed on a thumb drive
• More secure firefox defaults

You might download a developer snapshot from here. Please note: The developer snapshot might contain laxer privileges on some security settings and it is not in the update stream. Default language of the CD is German, you might change it to English by pressing Tab in the boot menu and appending lang=de.