HOWTO: Securly Clear Free Hard Drive Space with Scrub

[GrammatonCleric]

This how to covers the use of SCRUB, developed by Jim Garlick, to securly clear free hard drive space. Scrub uses user-selectable pattern algorithms that are compliant with DoD 5520.22-M or NNSA NAP-14.x.

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Step 1: Install Alien.


sudo apt-get install alienStep 2: Download Scrub.




Download Scrub (http://sourceforge.net/project/showfiles.php?group_id=153984)


Step 3: Convert RPM file to DEP.


sudo alien scrub_1.8-2_i386.rpmStep 4: Install scrub


sudo dpkg -i scrub_1.8-2_i386.debStep 5: Create a scratch directory for scrub.


sudo mkdir /scratchStep 6: Run Scrub (as root).


scrub -X /scratch/junk | sudo rm -f /scratch/junk

Updated: Updated download location.

[xyz]

Well it sure works but something got me very worried!

/dev/hda2 10080520 9952800 0 100% /

I had to Ctrl + C to stop it because I have a 5.3 GB 'junk' file!!
I misunderstood you, I guess. I thought it would free up space (as in unnecessary files) not the whole drive.
Anyone has an idea as to what I'm supposed to do to revert back? Thnx in advance.

PS: My backup is for Dapper; just upgraded this here machine to Edgy and, therefore I have no Edgy backup to restore.

[GrammatonCleric]

Scrub is not use to free up hard drive space. It's used to "securely wipe" free hard drive space. Say you have a bunch of sensitive data (i.e. patient files, financial data, deleted audio files before you send your hard drive to the RIAA =P, etc.) you may have deleted from your drive but you want to make sure the data is unrecoverable. Just because you delete a file does not mean it is unrecoverable.

How to recover deleted files:




http://e2undel.sourceforge.net/recovery-howto.html

Scrub will fill a partition gradually expanding and filling a single file with random data thus over witting any deleted files in that partition. If you read setup 7 you can simply delete the scrub junk file. =)

-GC

[xyz]

Yes indeed...I misunderstood you!
If you care to have a look:
I 'scrubbed my Ubuntu...' (http://ubuntuforums.org/showthread.php?t=376611)
I explain what I did there.

For some reason I don't understand it doesn't look like I lost data??
Thanks for your reply.

[bluebyt]

Does this clear Free Hard Drive Space on /Home partition?

[GrammatonCleric]

Does this clear Free Hard Drive Space on /Home partition?

It will "Scrub" whatever partition you output the junk file to. If your /home is in the same partition as your "/" then yes. If you have your /home mounted to it's own partition then you could run scrub like.



sudo scrub -X /home/junk
DON'T FORGET TO DELETE THE JUNK FILE WHEN SCRUB IS DONE.

-GC

[bluebyt]

It will "Scrub" whatever partition you output the junk file to. If your /home is in the same partition as your "/" then yes. If you have your /home mounted to it's own partition then you could run scrub like.



sudo scrub -X /home/junk
DON'T FORGET TO DELETE THE JUNK FILE WHEN SCRUB IS DONE.

-GC

I tried this "sudo scrub -X /home/junk" but I get this error:

scrub: scrub.c:204: scrub_free: Assertion `filetype(path) == NOEXIST || filetype(path) == REGULAR' failed.

[GrammatonCleric]

Can you post your partition layout? Run...




df -h


...from the command line and post the output.


--GC

[bluebyt]

Here you go:

df -h
Filesystem Size Used Avail Use% Mounted on
/dev/hda4 7.2G 3.9G 3.1G 57% /
varrun 506M 212K 506M 1% /var/run
varlock 506M 0 506M 0% /var/lock
procbususb 506M 88K 506M 1% /proc/bus/usb
udev 506M 88K 506M 1% /dev
devshm 506M 0 506M 0% /dev/shm
lrm 506M 26M 481M 5% /lib/modules/2.6.20-9-generic/volatile
/dev/hda3 12G 4.6G 6.2G 43% /home
/dev/hda1 19G 15G 4.3G 78% /media/sda1

[GrammatonCleric]

When you run...


sudo scrub -X /home/junkIs a junk file created? Scrub appears to be complaining about either the path/a missing output file (i.e. junk) or permissions to write to the path.

Try creating a junk file before running scrub....


sudo touch /home/junk or try doing ....


sudo -ithen run...


scrub -X /home/junk -GC

[bluebyt]

Didn't work same error message.

Thank you for helping me though!

[arijarot]

Thanks for this tutorial. Two questions. How can you tell if it did its job correctly. Is there a command to scrub the swap partition?

[Canuckelhead]

It's probably worth mentioning that if you happen to be using this on a FAT32 partition there is a 4 Gig - 1 byte file size limitation to consider. You'll need to change file systems...

[suba82]

Hi everyone, is it possible to use the same command line for a usb disk?
Cause I want to "scrub" free space on a usb disk plugged in my computer.
How can I choose the disk to wipe? thanx

[bigbooger]

scrub has been updated:

Scrub2.0 (http://sourceforge.net/project/showfiles.php?group_id=153984)