Making use of update*.tar.gz

[utu]

Thanks, dinosoep.

[utu]

Here's how well this experiment went for me:

Note, for perspective here, to reconstruct my favorite LiveCD from my
...Changelog notes 'by hand': 'ALL' manual changes might take hours;
...'All' manual changes: 10's of minutes; 'all' changes: just minutes.

GUI Software manipulations:
IceWeasel works, ALL changes retained; includes
...HomePage def'n, add-ons & deles, mail, passwords, bookmarks, history.
LXDE & PCManFM work, ALL changes retained; includes
...Desktop redefinition & tweaks to PCManFM.
Synaptic works, All changes retained; amounts to
...de->us repos, 2 programs removed, 2 added.
Network Manager & Broadcom wifi, All changes retained; includes
...SSID, WEP key, keyring password, Broadcom wl driver.
Compiz works, all changes retained.
LibreOffice spreadsheet works, all changes retained.

Command line tweaks:
Alsamixer, all edits retained
/etc/X11/Xsession, all edits retained.
/etc/syslog-knoppix.conf, all edits retained
/mnt-system/boot/syslinux/syslinux.cfg,' all edits LOST
...the ONLY item not transferred, since /mnt-system is not in KNOPPIX-DATA.

Here's how the two LiveUSB's compare:

Each goes from start-of-boot to on-line-with-wifi in 1m45s.
Each is 244 Mb smart in knoppix-data.img. Actually most of this 244 Mb
...is for an empty but necessary filesystem, and the bare essential files
...therein which any system needs to operate.

[Forester]

Hi utu,

Figured out what's going on here yet ?

While Knoppix is running, you've got a unionfs that comprises two halves - the read-only /KNOPPIX and the read/write /KNOPPIX-DATA. When you unzip your update tar file, where do you think the files in it go ? Into the empty /KNOPPIX-DATA of course and the backing store for that in your knoppix-data.img. So you end up back where you started. I don't think that is quite what you were trying to do.

You expressed surprise that you could delete you update tar file after first use. Actually you need to do this. Suppose you've tweaked Iceweasel and you've backed those tweaks up in your update tar file. First reboot, Knoppix will unpack the files in your update tar file so restoring your tweaks. Now suppose you tweak Iceweasol some more. You reboot without generating a new update tar file and without deleting the old one. Oops, Knoppix will unpack the files ... most probably obliterating your new tweaks. I imagine this would quickly become tedious.

Potentially worse is that you save to your tar file /KNOPPIX-DATA but Knoppix restores to /UNIONFS. Suppose you delete a package. It's not really gone. The UNIONFS writes a bunch of 'white out' files to the UNIONFS. When you tar up /KNOPPIX-DATA, you tar up all the white out files and any other hidden control files put there by aufs. When Knoppix applies your update tar file, it try to apply the white out files as if they were ordinary hidden file of no significant to aufs. A source of instability in the file system ? I don't think so, I think aufs will refuse to write such files to the UNIONFS and you'd get a bunch of error messages. The result is the deleted package reappears but may well be broken. This too could get tedious. As dinosep will tell you, deleted files should stay deleted.

Anyway, have a look at this post: http://www.knoppix.net/forum/threads...ersistent-data. This is not quite what you've been trying to achieve but it might be good enough for now.