Freeze SO Linux, it's possible?

Bart Silverstrim bsilver at
Thu Dec 11 15:49:02 UTC 2008

Loïc Grenié wrote:

>      I'm proposing (and myself using) something in between. I use a live CD
>   that is physically stored on an USB key.
>     There is a read-only filesystem stored on the USB key.
>     There is a read-write filesystem that can be stored in memory or on disk
>   or whatever.
>     Both partition are unioned with aufs (earlier it was unionfs). The resulting
>   partition is read-write, but nothing can occur to the read-only partition
>   (precisely because it is read-only). All modification you make to the
>   unioned partition (including file deletion) are stored on the read-write
>   partition. After eah session you can either choose to just throw away the
>   read-write partition (that's the way the live CD works) or keep it (if it is
>   stored on some kind of disk -- in which case you have a system very
>   similar to a usual one) or use the unioned partition to recreate a new
>   "read-only" partition (if you want to do an upgrade, update, installation
>   of software). This is "Live CD" but with the default system upgradeable
>   and stored on any medium (regular hard drive, CD, USB key, external
>   drive). I suspect it would fly on a regular disk (on the key it's a bit slow).
>     As far as I can tell it is very similar to Deep Freeze but it is probably a
>   bit more difficult to use: 

Definitely more convoluted in theory but once set up sounds workable in 
practice, as you know since you're doing it :-)

>I need to manually recreate the snapshot whe
>   I upgrade the system. When I've configured my USB key (~1.5 years ago,
>   it was with Feisty Fawn) I had to slightly modify the files of the initial
>   ramdisk because I did not really needed the exact same features of
>   Ubuntu Live CD; I don't know if the current initrd of Ubuntu is usable
>   directly.

Deep freeze is still easier to implement than what you're using since 
you had to do some modification (and DF is near native speed from what I 
can tell, whereas you already acknowledged slower performance. DF is 
also a little more transparent since you're keeping in mind what is RW 
and what is RO despite being unioned, no?

In other words this might not be an ideal setup for an average end user...?

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