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Help! Returning Macbook Air. Impossible to Securely Delete All Data?

V

VideoNewbie

macrumors 6502
Original poster
Feb 6, 2009
476
6
I know this is covered extensively on google. instructions say to "Reboot the system while holding Command and R keys - that should boot you into the recovery partition"

But how can i do a secure erase ? the option for doing a 3 pass or 7 pass secure erase is greyed out. how can i do a secure erase on the macbook air? (2012 mbair mountain lion)

furthermore i found this article saying ssd might be impossible to securely erase unless you physically destroy the disc? http://www.informationweek.com/news/storage/data_protection/229219009?cid=RSSfeed_IWK_All


help!
 
Hey,
I do not have an answer to your question, but I have returned 2 Macbook Air's in the past and I always just re installed the OS and left out my personal information. If you call them up, they will tell you that it is unnecessary since once it arrives it is reformatted anyways, but paranoia gets to me sometimes as well. Anyways hope someone helps you!
 
AFAIK you can't do a secure erase from the onboard partition.... You will need a recovery USB or CD and do it like that
 
The best option is to encrypt the drive using FileVault 2 and then do a regular format. That would make it much more difficult for someone to retrieve your data.
 
Even doing encryption using the disk utility then erasing will make it difficult to get at what you erased. Not worth anyone's time unless you tell them differently.
 
-

ok so far weve had 4 responses none of which really answer my question.
anybody else?
 
According to Apple

Note: With OS X Lion and an SSD drive, Secure Erase and Erasing Free Space are not available in Disk Utility. These options are not needed for an SSD drive because a standard erase makes it difficult to recover data from an SSD.

For more security, consider turning on FileVault 2 encryption when you start using the SSD drive.
 
VideoNewbie said:
-

ok so far weve had 4 responses none of which really answer my question.
anybody else?
Click to expand...

There's a reason traditional secure erase is disabled. First of all, it doesn't really work since an SSD controller won't allow the data to be completely re-written 3 or 7 times in exactly the same space. If it always allowed that, it would wear out the drive very quickly, and so it prevents it from doing so.

If your aim is to make the data unreadable, we have all given you a way to do it. Perhaps if you can boot into a Linux partition, there may be a way to run a SATA secure erase command, but note that the operation will take a very long time and it won't be easy to do and might brick the drive.
 
If you have another Mac boot the air into target disk mode and wipe it from the other Mac. I've done this with other macs but never a air.
 
The reason those options are greyed out is because there no point in doing them on an SSD.

On a spinning disk hard-drive with a regular erase, the data is actually kept on the hard drive while the space is marked as "free" or "available" for later use. Hence, we have these secure erase methods of purposely overwriting those sectors 3 or 7 or whatever number of times to make sure it's unreadable.

On an SSD, once the data is erased it's gone forever. There is no recovering deleted data. Unlike on a spinning disk hard drive, there is no physical/mechanical medium to look back to. Therefore, overwriting it any number of times is useless.

Just format the drive, and that's it.
 
oneMadRssn said:
Just format the drive, and that's it.
Click to expand...

You should mention that a quick format just erases the partition table. The data is still there physically. Just use a hex editor on the device and you'll see the raw data. Only a complete erase will completely remove all data. Completely erasing more than 1 time is silly though.
 
There should be no need for secure erase on Apple-supplied SSD. The native TRIM support ensures that the data is physically erased when the OS deletes it.
 
mayuka said:
You should mention that a quick format just erases the partition table. The data is still there physically. Just use a hex editor on the device and you'll see the raw data. Only a complete erase will completely remove all data. Completely erasing more than 1 time is silly though.
Click to expand...

If the data's still there, then what happens when you write new files? It wouldn't fit.
 
Blackberryroid said:
If the data's still there, then what happens when you write new files? It wouldn't fit.
Click to expand...

It overwrites it at that time. A quick format is like clearing the table of contents. It marks the entire drive as available to be written to. So even if there is data on 110 GB of a 120GB drive, it will accept a 20GB file because it will just overwrite space as necessary.
 
I dont understand why people freak out, when you format from disk utility just the regular erase. its not like you have fbi stuff or csi stuff on the computer or that its going in the hands of a russian spy, someone would have to know what exactly what they are doing to want to go in a returned computer to retrieve stuff and have a reason to, im a very careful person but is it me or do people over react here?
 
VideoNewbie said:
is there a correct way to format the drive? or do i just simply restart the computer while holding down command & r keys?
Click to expand...

Yes. Boot using command-r, then launch disk utilities from the menu bar and erase the drive. Don't do the "quick" erase, just the regular one (I think it's called "zero out data").

To put it simply: if the disk get erased, then you did it right. There is no wrong way to format a drive.
 
Zeroing out a ssd is absolutely pointless.

Encrypt
The drive (which will take less time) using FileVault and then boot and delete the partition.
 
h00ligan said:
Zeroing out a ssd is absolutely pointless.

Encrypt
The drive (which will take less time) using FileVault and then boot and delete the partition.
Click to expand...


what if i did an encrypted format? (too late to encrypt the drive didnt do that before erasing)
 
VideoNewbie said:
what if i did an encrypted format? (too late to encrypt the drive didnt do that before erasing)
Click to expand...

It could help to write random data to the SSD. the linux tool "badblocks" can do that. You'll have to compile it yourself, though it runs on OS X too.
 
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