hi zeppo,
These past years I have been using a live system using multiple layers of aufs ( formally unionfs ) since kanotix, sidux, aptosid and now siduction. for example the system I am writing to you now on has these layers:-
siducer@siduction:~$ ls-auf-fs.rb
Mount Point: /fll/aufs
si Ident : si=ebebb4dc
/fll/cow (rw)
/fll/livedevp2/siduction11-1-kde/test32/h1 (ro)
/fll/livedevp2/siduction11-1-kde/test32/h0 (ro)
/fll/livedevp2/siduction11-1-kde/test32/99-usr-local-bin (ro)
/fll/livedevp2/siduction11-1-kde/test32/8-git-gui-aufs-shwh (ro)
/fll/livedevp2/siduction11-1-kde/test32/7-vlc-reinstall-youtube-mathomatic (ro)
/fll/livedevp2/siduction11-1-kde/test32/6-adjust-prev-ffmpeg-etc (ro)
/fll/livedevp2/siduction11-1-kde/test32/5-ug-programming-kdev-etc (ro)
/fll/livedevp2/siduction11-1-kde/test32/4-libreoffice-with-dpkg (ro)
/fll/livedevp2/siduction11-1-kde/test32/3-kidsgames-edu-extras (ro)
/fll/livedevp2/siduction11-1-kde/test32/2-ug3-ruby-utils (ro)
/fll/livedevp2/siduction11-1-kde/test32/1-ug2-synaptic-essent (ro)
/fll/siduction (rr)
siducer@siduction:~$
In my /fll/livedevp2/siduction11-1-kde/test32/ directory I have these files directories and links
siducer@siduction:/fll/livedevp2/siduction11-1-kde/test32$ ls -l
total 127964
drwxr-xr-x 2 root root 4096 Feb 1 04:27 0
lrwxrwxrwx 1 root root 22 Feb 1 03:27 1 -> 1-ug2-synaptic-essent/
drwxr-xr-x 2 root root 4096 Jan 17 20:58 1.sqfs.dir
drwxr-xr-x 8 root root 4096 Jan 13 18:52 1-ug2-synaptic-essent
lrwxrwxrwx 1 root root 17 Feb 1 03:27 2 -> 2-ug3-ruby-utils/
drwxr-xr-x 9 root root 4096 Jan 13 20:13 2-ug3-ruby-utils
lrwxrwxrwx 1 root root 23 Feb 1 03:27 3 -> 3-kidsgames-edu-extras/
drwxr-xr-x 8 root root 4096 Jan 14 12:51 3-kidsgames-edu-extras
lrwxrwxrwx 1 root root 24 Feb 1 03:28 4 -> 4-libreoffice-with-dpkg/
drwxr-xr-x 8 root root 4096 Feb 1 03:27 4-libreoffice-with-dpkg
lrwxrwxrwx 1 root root 26 Feb 1 03:28 5 -> 5-ug-programming-kdev-etc/
drwxr-xr-x 8 root root 4096 Feb 1 03:27 5-ug-programming-kdev-etc
lrwxrwxrwx 1 root root 25 Feb 1 03:28 6 -> 6-adjust-prev-ffmpeg-etc/
drwxr-xr-x 8 root root 4096 Jan 25 04:32 6-adjust-prev-ffmpeg-etc
lrwxrwxrwx 1 root root 35 Feb 1 03:28 7 -> 7-vlc-reinstall-youtube-mathomatic/
drwxr-xr-x 8 root root 4096 Jan 25 05:29 7-vlc-reinstall-youtube-mathomatic
lrwxrwxrwx 1 root root 20 Feb 5 18:07 8 -> 8-git-gui-aufs-shwh/
drwxr-xr-x 9 root root 4096 Feb 3 13:41 8-git-gui-aufs-shwh
lrwxrwxrwx 1 root root 17 Feb 6 22:32 9 -> 9-joomla-2.5.0-1/
lrwxrwxrwx 1 root root 17 Jan 30 04:33 99 -> 99-usr-local-bin/
drwxr-xr-x 3 root root 4096 Feb 1 02:16 99-usr-local-bin
drwxr-xr-x 4 root root 4096 Feb 6 22:28 9-joomla-2.5.0-1
-rw-r--r-- 1 root root 109883392 Feb 7 02:55 9-joomla-2.5.0-1.sqfs
drwxr-xr-x 3 root root 4096 Jan 10 22:48 archives
lrwxrwxrwx 1 root root 19 Jan 12 20:37 base-mount -> ../../../siduction/
drwxr-xr-x 3 root root 4096 Jan 27 22:50 chroot_scripts
etc...
As well as patching fll as described previously I have also added the functionality to add the layers at boot time, ( I have not yet decided on a final method ) at the moment here is the relevant boot menu.
It's grub4dos because I like to be able to just edit it with text editor.
title AUFSPATCH SCRIPTS-LAYERS-siduction-20120122 kde live on livedevp2
find --set-root --ignore-floppies /livedevp2.tag
kernel /siduction11-1-kde/vmlinuz0.686 boot=fll image_dir=siduction11-1-kde image_name=siduction-sqfs-kde-base-ug-20120122.686 quiet vga=791 keytable=gb tz=Europe/London fromhd=LABEL=livedevp2 firmware aufs layers_dir=/siduction11-1-kde/test32 layers=1,2,3,4,5,6,7,8,99,h0,h1
initrd /siduction11-1-kde/aufsnew-initrd0.686
From above you can see layers, so far 1 to 8 is software added ( sequentially ) over time.
layer 99 is just a few scripts added to /usr/local/bin
layer h0 and h1 are layers concerning home directory for example, firefox flash and plugins configs of kde etc. and a few links to often used file and directories on other partitions.
Now when I wan't to add new software ( It could be something i really want, or just be on a whim, an experiment, just for the hell of it ).
remount the partition rw
Create a new directory say mkdir /fll/livedevp2/siduction11-1-kde/test32/10-example-experiment
and a link to it ln -s 10-example-experiment/ 10
Create a chroot that will inlude the layers I'm running on and the new layer ( but not the home layers h0 h1 ).
a comandline to show for completeness:-
mount -v -t aufs -o br:10/=rw:8/=ro:7/=ro:6/=ro:5/=ro:4/=ro:3/=ro:2/=ro:1/=ro:0/=ro:base-mount/=ro none rt_chroot/
Now all the aufs mounts are:-
root@siduction:/fll/livedevp2/siduction11-1-kde/test32# ls-auf-fs.rb
Mount Point: /fll/aufs
si Ident : si=ebebb4dc
/fll/cow (rw)
/fll/livedevp2/siduction11-1-kde/test32/h1 (ro)
/fll/livedevp2/siduction11-1-kde/test32/h0 (ro)
/fll/livedevp2/siduction11-1-kde/test32/99-usr-local-bin (ro)
/fll/livedevp2/siduction11-1-kde/test32/8-git-gui-aufs-shwh (ro)
/fll/livedevp2/siduction11-1-kde/test32/7-vlc-reinstall-youtube-mathomatic (ro)
/fll/livedevp2/siduction11-1-kde/test32/6-adjust-prev-ffmpeg-etc (ro)
/fll/livedevp2/siduction11-1-kde/test32/5-ug-programming-kdev-etc (ro)
/fll/livedevp2/siduction11-1-kde/test32/4-libreoffice-with-dpkg (ro)
/fll/livedevp2/siduction11-1-kde/test32/3-kidsgames-edu-extras (ro)
/fll/livedevp2/siduction11-1-kde/test32/2-ug3-ruby-utils (ro)
/fll/livedevp2/siduction11-1-kde/test32/1-ug2-synaptic-essent (ro)
/fll/siduction (rr)
Mount Point: /fll/livedevp2/siduction11-1-kde/test32/rt_chroot
si Ident : si=f0224edc
/fll/livedevp2/siduction11-1-kde/test32/10-example-experiment (rw)
/fll/livedevp2/siduction11-1-kde/test32/8-git-gui-aufs-shwh (ro)
/fll/livedevp2/siduction11-1-kde/test32/7-vlc-reinstall-youtube-mathomatic (ro)
/fll/livedevp2/siduction11-1-kde/test32/6-adjust-prev-ffmpeg-etc (ro)
/fll/livedevp2/siduction11-1-kde/test32/5-ug-programming-kdev-etc (ro)
/fll/livedevp2/siduction11-1-kde/test32/4-libreoffice-with-dpkg (ro)
/fll/livedevp2/siduction11-1-kde/test32/3-kidsgames-edu-extras (ro)
/fll/livedevp2/siduction11-1-kde/test32/2-ug3-ruby-utils (ro)
/fll/livedevp2/siduction11-1-kde/test32/1-ug2-synaptic-essent (ro)
/fll/livedevp2/siduction11-1-kde/test32/0 (ro)
/fll/siduction (ro)
bind mount these directories:-
mount --bind /tmp rt_chroot/tmp
mount --bind /dev rt_chroot/dev
mount --bind /run rt_chroot/run
enter the chroot:-
chroot rt_chroot
run a script in the chroot to mount these:-
mount -t proc none /proc
mount -t sysfs none /sys
mount -t devpts none /dev/pts
apt-get update
apt-get install any_sotware_you_want
before you leave:-
umount /proc
umount /sys
umount /dev/pts
exit the chroot:-
exit or ctrl-d
Make sure you are not accessing the chroot with say a file manager, and umount the binds and the chroot:-
umount rt_chroot/tmp
umount rt_chroot/dev
umount rt_chroot/run
umount rt_chroot
Occasionally the rt_chroot will not unmount because of open processes, you can:-
lsof rt_chroot
and kill them
Next time you boot to test out the added layer boot with
layers=1,2,3,4,5,6,7,8,10,99,h0,h1
Ok it might just have been an experimental test of some software, but remember you have an instant and better version of "microslops system restore" ( thats instant and reverseable ). ie. Just don't boot the end layer/layers in your sequence.
Ok assume now I have all the software I need, and I want it portable on a pen drive - but it's way too big in these layers of directories, I even have over 1gig of debs in these layers.
I go through the same steps as above but instead of adding a new software layer, add a new cleanup layer eg 10-cleanup/
In the chroot, apt-get clean and purge. Clean out the logs etc. if you want to ( hint you can look in /fll/siduction to see whats in the original squashfs file as a guide ).
Unmount internal directories come out of the chroot and unmount the binds but do not unmount the aufs chroot.
You are now ready to rebuild a main squashfs file ( some would call it a poor mans or frugal rem*st*r ) is that word allowed here?
mksquashfs rt_chroot my-big-bloated-new-siduction.sqfs
Replace squashfs on pen drive with new one and adjust names and or boot menu as appropriate.
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With the changes in the initrd0.686 outlined in the previous post:-
adding one line to initrd0.686 /etc/default/distro
changing 2 lines and adding 5 lines of code to initrd0.686 /scripts/fll
Will enable the following ( without changing the current style which is a squashfs file which now contains a sparse ext4 filesystem file )
In dmsetup live mode not changed ie. "virtual" layer using dmsetup:-
Still has the same usabillity of being an ideal way to quickly get a full HD install of up to date debian sid.
The same functionality of creating live system installed to pendrive etc.
added - the image_dir and image_name boot code now works.
Added functionallity
If you boot with the aufs boot code you have a live system using aufs:-
Ability to add as many aufs layers as you want.
Examine the files in the individual layers
Persistance works by just naming a persistant directory ie persist=siduction/my-persist.
Easy rebuilding of the base squashfs file.
Lots more options to experiment with, and have fun with live systems, if you want to.
Also still has the ability to use the previous style of squashfs file.
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As you can see on my system I have already added more, and am testing and refining:-
Automatically adding multiple layers with boot code.
Calling named scripts on HD with boot codes.
Mounting layers compressed into squashfs or other filesystems.
Easy adding self-contained modules like xampp
www.apachefriends.org and the many and various BitNami stacks bitnami.org/
All potentially able to run from a live system.
ian_s
