Leo: tecnologia e gadget per stare comodi

Ogni distribuzione ha una versione “live” per permettere di verificare, provare e studiare come funziona e se è la distro che fa per noi.
Però una volta trovata la nostra distribuzione, una volta che l’abbiamo personalizzata con i programmi che ci interessano e liberato dei programmi che riteniamo inutili sarebbe una gran cosa poterla ri-trasformarla in una “distro” live.
Ovviamente su internet c’è già qualcuno che ci ha pensato e ha creato una serie di script per poter trasformare la nostra installazione in una distro live, il sito di cui stiamo parlando è www.linux-live.org

Linux Live è un insieme di shell script che permette di creare la tua propria distribuzione live, partendo da quello che è già stato installato sul pc. La live sarà di tipo bootable sia da cd-rom che da qualsiasi sistema usb.

Di seguito le istruzioni prese direttamente dal sito.

How to build a Live distro:
1) Install your favourite distro to disk partition, or into a folder on your existing system.
Slackware is recommended but not required.

2) Build aufs kernel module and squashfs kernel module (optionally patched to support LZMA)
The step above is not required if you use precompiled Linux Kernel from this website
Install kernel modules to the newly installed distro to /lib/modules/`uname -r`/fs/.
Make sure you are running the same kernel you used to compile modules

3) Remove all unnecessary files (for example man pages and all other files you don’t need),
to make your Live Linux system as small as possible (this step is optional).

4) Download Linux Live scripts from this website and unpack it in /tmp
Read ./DOC/requirements.txt to find out what linux-live scripts need
Edit .config file if you need to modify some variables

5) Finally login as root and run ./build
Live distribution’s ‘directory tree’ will be created in /tmp/live_data_1234
where 1234 is a random number

6) To make ISO image, run make_iso.sh
To make a bootable (usb) disk, run bootinst.sh

Working example:
If you’re just looking for a working Linux Live system, visit www.slax.org
Interesting features of Linux Live scripts

1) persistent changes
Use ‘changes=…’ boot parameter to specify persistent changes directory or file. If a directory is used, eg. changes=/some_dir/ and the /some_dir/ is found on some partition on your disk, then all the changes made to the root filesystem will be saved to that directory. This works even if /some_dir/ is on NTFS or VFAT, thanks to posixovl overlay (an userspace filesystem, already included). Important note: if you plan to save changes on VFAT, make sure to modify your distribution’s shutdown scripts. It must not execute killall, else posixovl is killed and everything is wrong. Instead, call the cleanup script from /mnt/live/cleanup. If a file is specified for the changes boot parameter, eg. changes=/path/file.dat, and the file has a valid filesystem inside, then the file will be loop-mounted and changes written to it. You may also use changes=/dev/sda1/path/ and changes=/dev/sda1/path/file.dat … to specify particular device where to look for. Other devices will be skipped (will not be even mounted).

2) adding modules on the fly
In the ./tools/ directory of Linux Live, you will find ‘activate’ and ‘deactivate’ scripts. You may use these two to add and remove additional LZM modules to the root filesystem on the fly, while your Live OS is running.

3) installable system to disk
As mentioned in the previous section, there exists a script called bootinst.sh (and bootinst.bat) to setup a boot sector to boot Live Linux from disk. If you combine that with persistent changes, your Live distro will behave like INSTALLED, all changes are transparently stored to the boot media (even to USB), and you can still use ‘activate’ and ‘deactivate’ commands to manipulate the root filesystem.

Cosa ne pensate? Qualcuno di voi ha già provato ad usarlo?

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