lesslinux.org Development Blog

So now you are ready building the chroot environment – then it is time to assemble the final ISO. To do this you need an overlay containing some configuration files for the bootloader. I packaged such an overlay for the current LessLinux Search and Rescue: lesslinux-search-and-rescue-uluru-20110202-155012-overlays-en.tar.bz2. You’ll find more recent overlays here: http://download.lesslinux.org/overlays/, but when building care that overlay and buildscripts match. Unpack the overlay in the folder /mnt/archiv/LessLinux. Mehr »

Besides the switch to SQLite there are other big changes regarding the build of stage02, which is the population of the chroot environment:

• LessLinux now supports tracking of dependencies after building packages. This allows to define the order of packages to build.

• As a consequence of the dependency tracking it is now also possible to parallelize the build. On a three core Athlon this brought down build times from around three days to less than 20 hours. With a faster machine you should even get better results.

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Many changes were added since my first description of how to build LessLinux. There are two major changes that are worth noting most:

• We switched from MySQL to SQLite3 as database during build

• LessLinux is self containing now, this means you can use LessLinux to build LessLinux to build LessLinux…

The stage01 build of LessLinux very closely resembles the chapter Chapter 5 – Constructing a Temporary System from Linux from Scratch. You’ll even notice similar environment variables. There will always be slight differences in package versions – this is intended. So you might be able to build LessLinux on any machine equipped with the right programs to build Linux from Scratch. But in my opinion do one of the two following things: Mehr »

I am proud to present release 1.5 of LessLinux Search and Rescue. This is the first stable, open and free release from a series of rescue and recovery systems previously featured in magazines like Computer Bild. The CD targets both users unfamiliar with linux who are in search of a easy to handle live system as well as administrators or anyone familiar with linux. For the latter group the command line offers tools found on every better rescue system, but also many “cheatcodes” (boot options) to enable netboot or remote administration via VNC. The former group finds some convenient graphical wrappers for typical tasks like resetting Windows passwords or wiping hard disks.

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Please do not think I didn’t work on LessLinux in the last weeks! On September 15th there will be a large press conference, where a new, LessLinux based distribution will be unveiled. Some features of this distribution are now available on current development builds. I am proud to present a development build that nicely demoes this new features:

• 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

Do you also have some relatives that always ask for “family support”: When you come to their house, you find a totally f***ed up Windows XP machine with tons of spyware and you’ll get to hear “I did not do anything”. The worst part of it: While you do the work, they keep talking at you.

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.

After adding support for netbooting LessLinux by downloading the ISO image via HTTP/FTP I can announce support for NFS boot. For this feature you just need to add

        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.

This article targets mainly readers from Germany and Austria, thus it is in German. The topics “user support” and “financial contributions” will soon arise for other users as well, then a similar article in English will follow.

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. Mehr »

As mentioned previously, support for netbooting LessLinux was recently introduced. In builds from 20100528-000000 it works stable and can be used in production environments. So please test the new function with this build:

• 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: Mehr »

As I mentioned before, “LessLinux Search and Rescue” is intended to be a versatile live system for typical service jobs that have to be done in mixed environments. To make work easier, a service system should be net-bootable and accessible with a remote desktop application. In builds starting with timestamps after 20100526-000000 I included support for both functions:

• 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

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