I want to upgrade a few drives, and sell off the old ones.

Now I want to sell the harddrives, without personal documents and extensive porn collection.

(Building a high quality and diversified porn collection is hard work and it builds charcter)

 

I would like a button "wipes disk - prepare for E-bay" that completely wipes a disk of any traces.

 

/Rene

 

 

 

My thoughts? Too risky, too easy to accidentally lose data. I'd put the drive in a different machine as the only hard drive attached, and run dban off of a boot cd.

http://www.dban.org/download

Get a $15 external drive bay, and use it to hook the drive up to another system (Windows) and wipe it there.  BCWipe is good.

Do what i do....put them on a shelf and forget about them. The wipe utils are very very good and stop people recovering data but not all people and not all data.

 

In my opinion its just not worth it but i don't even RME drives so im an extreme case.

 

Saying that i can see it being useful to some people but something this dangerous has no place on unRAID. One day one user would do it by mistake and thats one user to many.

 

Sorry

My thoughts? Too risky, too easy to accidentally lose data. I'd put the drive in a different machine as the only hard drive attached, and run dban off of a boot cd.

http://www.dban.org/download

 

I'm not sure wipe function on unRAID is the best approach

I would have to go with this recommendation, I use dban also.

 

 

Although I would like a clear function to remove a drive from the array gracefully. part of me just can't help think that someone someday is going to press that button when they shouldn't.

 

I really would like a way to remove a drive from the array gracefully. (If it's erased or not us up for debate).

 

 

I do forensic data recovery for a living.  The stories you hear about the ability to recover overwritten data are just that -- stories.  No one outside CIA/NSA can do it.

 

A single-pass random overwriting of all sectors is otherwise sufficient.  If you are paranoid, do 2 passes.

I do forensic data recovery for a living.  The stories you hear about the ability to recover overwritten data are just that -- stories.  No one outside CIA/NSA can do it.

 

A single-pass random overwriting of all sectors is otherwise sufficient.  If you are paranoid, do 2 passes.

 

I've always figured as much.

Do what i do....put them on a shelf and forget about them. The wipe utils are very very good and stop people recovering data but not all people and not all data.

Yery true, although if you write zeros or ones to the entire drive, it will be difficult for anybody but a government lab to get to anything remaining.  The issue being any residual data left to the left and right of the data track that was not entirely erased.  To read it, you would really need to be interested...  really, really interested.

Saying that, I can see secure clearing being useful to some people, but something this dangerous has no place on unRAID. One day one user would do it by mistake and that's one user too many.

Sorry

I agree, too easy to choose the wrong drive if permitted... even if you do this all the time. 

 

One possibility is to only allow the function if the drive "is not part of the array" and is unassigned.  Then, if the array status is valid, and the disk is not part of it, but connected to one of the disk controllers, it would be pretty safe.

 

I can easily add that ability of writing zeros to a drive to the "Unassigned Disk" management page in the "unmenu.awk" server.  I know Tom has said in the past that there is a way to zero a drive AND mark it in some way that the unRAID array does not need to do a lengthy pre-clear step to add it to an array.

 

I think that exact type of pre-clearing of a drive might serve both purposes. 

 

* To ready a drive so it can be added to an existing array with seconds of down-time rather than hours of off-line time clearing a drive.  (It will still take hours to clear the drive, just it will be done with the unRAID array still running, so your family can still watch their movies, etc.)

* To clear a drive prior to sale, re-allocation, etc.

 

Thoughts?  It is a pretty easy addition to the unmenu.awk server, in fact, hardest part is to get from Tom the special "signature" he writes to pre-cleared drives to unRAID can tell they've been pre-cleared. 

 

This might serve both needs, one far more of interest to most unRAID users... less down-time adding a drive to the array. The drive can be pre-cleared before adding it to the array.  The other, to clear a drive AFTER removing it from the array. 

 

In any case, the web-page would never allow a clear process on a drive in the array, and in that way, be way less likely for somebody to accidentally zero a drive.  (not impossible to accidentally destroy data)

Perhaps I can add an "are you sure", "are you sure you're sure," "are you really really certain you're sure" series of buttons.

 

Joe L.

I do forensic data recovery for a living.  The stories you hear about the ability to recover overwritten data are just that -- stories.  No one outside CIA/NSA can do it.

 

A single-pass random overwriting of all sectors is otherwise sufficient.  If you are paranoid, do 2 passes.

 

Thats quite a statement. So your saying not one data recovery company and subsequently their employees can possibly do this? Obviously your answer is going to be "it is possible but remote" and that seems sensible but for me at least the remote possibly is too much.

 

Theres a couple of case studys I was given by company's in my game that purchased second hand drives from ebay and analysed them. Will see if I can find them and if they are covered by any NDAs.

So your saying not one data recovery company and subsequently their employees can possibly do this?

 

Yes... I am.  No equivocation.  A drive completely overwritten with random data, just once, can not be recovered by any of them.  Period.

 

Several forensic examiner groups have a substantial prize waiting for anyone who can recover data from a "wipe-once" drive.  Anyone with that ability would be an instant celebrity in the field, and lawyers would be beating down his door to hire him.

 

Any data recovered from a second-had drive was due to improper wiping of the drive.

I love this statement in the DBAN FAQ 

Sure gave me a chuckle.

 

If you are seriously concerned about any of these situations, then consider drilling open your hard disk, grinding down the platters, and melting all of the parts in a furnace.

 

I do know people that went through similar methods to insure the data on the hard drive would not be physically recoverable.

 

 

Considering how much a reiser filesystem can be recovered from disasterous mistakes, there is a point to wiping the disk.

 

you can always remove the disk from the array.

Then use the dd command (being very careful of couse).

 

 

dd if=/dev/zero of=/dev/sd? where ? = drive letter of drive you want to write 0's over.

 

This assumes you have stopped the array and removed the drive from the devices page.

Do not do this while a drive is part of the array or actively defined in the array.

 

Also there is a linux command called shred which can do this also.

It's not in unRAID, therefore you would have to acquire it somehow and install it.

 

Too dangerous ?

It makes a fair amount of sense to have a procedure for "exiting" a disk including a wipe.

 

Windows tools, external cages, put it on a shelf ??.

Lets say that I never mentioned selling, and it is my religion that forbids me to have disk outside a chassis containing data. So I have to wipe disk before it leaves chassis.

BTW it is a well know fact that electrical waste containing data, is more dangerous to the environment that if it is cleaned. It takes nature around 150 years extra to breakdown a disk if it contains lots of data. Encrypted data is even worse...

 

Anyway, Is there a command I can run from Telnet to wipe a disk ?

/Rene

Absolutely easy from telnet to write zeros to a drive.

 

Somewhat more difficult to ensure you are writing zeros to the CORRECT drive.

 

If you know the Linux device of the disk, (which will be /dev/hda, /dev/hdb, etc or /dev/sda, /dev/sdb, etc... it is easy.

 

Before you do this... make sure you have the correct drive.  It should NOT be part of your array, in other words, either it has never been in your array, or has been replaced with another and is no longer assigned in any way on your "Devices" page.

Before you do this,remember it cannot be undone, and as mentioned, if you choose the wrong drive, you will cause LOTS of grief for yourself.

 

the command is:

dd if=/dev/zero of=/dev/your_disk_to_be_erased

 

where /dev/your_disk_to_be_erased is /dev/sda,b,c,d,e,f,g,h,i,j,k,l... or /dev/hda,b,c,d,e,f,g,h,i,j,k,l,...

 

I plan on adding a way to do this from within the unmenu.awk web-server pages that is a tiny bit safer in that it will not let you choose a drive assigned in your array.  Please wait for it, or be very careful. 

 

Joe L.

(Why do I feel like I've just left matches and dynamite out where a 4 year old child can get to them?)

 

 

There is a way to ensure the safety of a remove and wipe procedure, and that is to REQUIRE that the drive be completely empty, that is, absolutely no files or even folders.  By adding this requirement, there is no risk of data loss or corruption.  Even if a user happens to have another empty drive, and selects the wrong one, there is still no risk of data loss, because it's empty!

 

I like Joe's suggested clearing plugin, and would like to suggest that he also consider such a requirement.  This way, the user has to be knowledgeable enough to select the correct drive and manually delete all of its files and folders.  That should remove any chance of a mistake, and is not too onerous for the experienced users among us.

 

Unfortunately, Joe's method will only apply to drives already outside of the array, and I think most who want a wipe procedure, will be mostly interested in removing and wiping array drives.

 

All of which brings us to the need for a safe and quick way to remove a drive from an array.  I outlined a way elsewhere, but I'll summarize here.  It acts similar to a parity check and sync, except that it only reads the data drive to be removed, and reads and writes the parity drive, so should be somewhat quicker, with much less bus contention.  It reads the same block from the data drive and the parity drive, corrects the parity info, then writes the parity block back to the parity drive.  All it has to do for parity processing is flip every parity bit that corresponds to an on bit from the data drive, and that is easy by XOR'ing the 2 blocks together.  The one bits ensure that only those corresponding parity bits are reversed.  The resultant block is the corrected block to write to the parity drive.

 

Like a parity rebuild, that procedure CANNOT be interrupted, or the parity drive is garbage.  If we call that procedure something like Remove Drive (what originality!), we could call a second procedure Remove and Clear Drive.  It would not be nearly as fast, but it would proceed just like Remove Drive, except that after writing the new parity block back, it would also write a cleared block to the data drive.  Although slower, this procedure would actually be safer, because it would even be interruptible, that is, parity would be good at all times.  An interruption would only risk at most one parity block, and a parity check would fix that.  Plus, the drive ends up completely zeroed.  Each of these procedures finishes by un-assigning the drive.  For now, only Tom can add procedures like these.

 

Those who might want additional wiping passes, can use a user script that someone could create, that writes random gibberish to all blocks.

My remarks in the post above have strayed off-topic, I apologize.

 

The primary subject of this thread has been added to the FAQ (with a link back), here.  Feel free to edit.