Freeze SO Linux, it's possible?

Bart Silverstrim bsilver at
Thu Dec 11 17:10:24 UTC 2008

Loïc Grenié wrote:

>     I have slower performance because I'm using an USB key (program loading,
>   data writing is all done on my USB key and it's slow). If you use a hard-disk
>   for the read-only partition and memory for read-write, it's probably roughly
>   the same speed as a regular linux (memory fills while you use the system,
>   so it might become slow after a while, especially if you download
> large files).

True. I was thinking your main advantage to the USB key though is ease 
of cloning and backing up rather than a hard disk.

My concern is figuring out if someone clever would find a way to have it 
mount the hard disk R/W on reboot without someone noticing, while CD's 
and hardware-lockable-RO USB drives would thwart this.

DF I guess has had a couple attempted hacks, but for the most part is 
pretty good about not being bypassable, maybe as long as you don't allow 
booting from CD-ROM or other devices. Your proposed method is something 
I'd have to ponder and see how comfortable I'd be with that method.

>   If you use a disk partition for both partitions it's probably the
> same speed as
>   a regular Linux (maybe slightly slower on slow processors) -- in that case the
>   read-write partition must be reformated at each boot, though.

Then you get into arguments over slack space :-)

I don't know exactly how DF works and no one seems to come forward with 
explanations. I'm half tempted to see if anyone can get an email 
forwarded to Mark Russinovich (spelling?) to see if he's ever looked at 
it and would be willing to come forward with theories.

>      Only when you create the setup or when you want to update/upgrade
>   it. At regular run-time, you don't need to know. The system boots like
>   any Linux system, except that changes don't survive reboot.

Good point, but I think the update and upgrade part is frequent enough 
that it would drive me batty :-)

>> In other words this might not be an ideal setup for an average end user...?
>      This is definitely not an ideal setup for an average end user, but Deep
>   Freeze on Linux is not a very useful program for the average end user. It's
>   doable for a motivated system administrator (or hacker, in the positive
>   sense). After the initial setup, which was a pain for me (but I know it's
>   easier now, but I don't know how much easier) it's not difficult to use,
>   even when you want to update the "read-only" part.

It's a niche thing. Locking out changes is a niche no matter what...we 
use it because we have two or three people working to administrate 800+ 
systems used by students and faculty, so it's to reduce support problems 
with malware and users altering settings and claiming they don't know 
how XYZ was installed or settings were altered.

For private use I'll stick to virtual machines and snapshots, but 
otherwise locking out changes and etc. etc. are more of a hassle than 
I'd want to deal with on a personal system.

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