deep freeze clone

[JakeFrederix]

Hi everyone,

I'd like to make an open-source version of a program called "Deep Freeze".
Basically it prevents users from making permanent changes to a computer.
Convenient for computers in libraries, public places, ...

You can still do pretty much anything with the computer, but as soon as you reboot it, all changes have gone.

So, I was thinking of going about it this way;
1) monitor each harddrive, when a change is made log it to a hidden file
2) at startup, read the logfile, reverse all

I know this is a bit simple (and the log file poses a security gap), but it's a good start.
I cannot find any way to monitor changes on the harddrive though.

I'd program this in C++ by the way.

Anyone got any ideas?

Jake

[viralmeme]

I'd like to make an open-source version of a program called "Deep Freeze". Basically it prevents users from making permanent changes to a computer.

No need to write your own app, you can already do that with the current Ubuntu,. Just create a standard user and add a line to .bash_logout to remove any newly created files at logout.

[JakeFrederix]

Perhaps I should clarify.
I want to make this application available not only for Linux, but for Windows as well as Mac. I see no reason not to share such a good utility.
Also, most libraries or computer in public places run Windows.

[Sporkman]

Just keep a backup disk image somewhere, then for each file on the system, if the modification date > the backup image's file's modification date, copy the backup file over to the current one.

Or perhaps have rsync do that for you...

[JakeFrederix]

Backing up the entire disk is an expensive (in terms of algorithmic cost) operation.
It would be easier to restore only the affected areas.

[viralmeme]

Backing up the entire disk is an expensive (in terms of algorithmic cost) operation.
It would be easier to restore only the affected areas.

You could try running a chroot environment and reset that at each logout ..

en.wikipedia.org/wiki/Chroot

[theozzlives]

You maybe can set a mandatory profile where changes cannot be made. I don't know if that is possible in Mac, as I have never worked with a Mac.

[HermanAB]

Use Virtualbox and every night, restore the VM from a tar ball.

[JakeFrederix]

I am not looking for suggestions on how to go about implementing this clone.
Storing an archive, mirror, resetting everything to default, all are good suggestions, but they are not what I want.

I am looking for a driver I can put over a harddisk, that will record any changes made.

Kind regards,
Jake

[Sporkman]

I just saw this package in synaptic, & it reminded me of this thread:

loggedfs

Fuse-filesystem daemon logging every filesystem operations

LoggedFS is a transparent fuse-filesystem which allows you to log every
operation that takes place in the backend filesystem. Logs can be written
to syslog, into a file, or to the standard output.

You can add filters to an XML file to filter on users, operations (open,
read, write, chown, chmod, etc.), filenames and return codes.
Since it is fuse-based, you don't need to change anything in your kernel
or on your hard disk partition to use it.

This of course only applies to linux. In the linux case, maybe you could process the operations from the log output, and restore backed-up versions of modified files. Or, hack the package to do other stuff above & beyond the logging.