Guide | How To How to securely erase the data from SSD drives

[LaserWraith]

Ask Ars: How can I securely erase the data from my SSD drive?

How can I safely erase the data from my SSD drive? I've seen a few pieces in recent days about how traditional "secure delete" programs fail to work properly on SSD drives, so what tools are available and useful?

As pointed out in a recent research article, there isn't a standard method for securely deleting data from a solid state drive. Hard disk drives have had this problem solved for ages, and can execute a secure delete by filling the space occupied by an incriminating file with zeroes or multiple writes of different characters. We'll go into why this approach and some other secure erase methods don't really work on an SSD, especially not for individual files, and then describe some approaches you might take to make sure all your old data is gone for good.

We did an Ask Ars not long ago concerning the way that SSDs handle deletion and cleanup of old files, and we'll assume you've read it or have equivalent knowledge. Basically, the issue with SSDs is this—let's say your SSD is a pirate, and your data is buried treasure. If you tell an SSD pirate to make his buried treasure disappear, all he really does is burn the treasure map. The buried treasure is still out there for someone to find if they know where to look. This isn't the case for all SSDs in the long term, but it is the case for all of them in the short term.

Some SSDs get around to destroying things like old versions of files with garbage collection, and some can take care of deleted files with TRIM, but because an SSD's only immediate reaction to a deleted file is to forget where that file is rather than erasing it, files can sit scattered around an SSD for a while. Deleting files immediately would cause extra wear on an SSD, which is why they don't do it.

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I don't have one, but might be useful to some.

 

[bogdan]

It seems that manufacturers try to overcome the limited number of writes you can have on a solid state drive (or with any another flash based storage device like USB stick, memory card...etc) and the slower over-writes (writing occurs much faster if the data is placed in a space that never contained anything) and they optimize the SSD by avoiding over-writing when possible, to make the drive faster and increase its lifetime. The drawback is that secure-erase methods that worked for HDDs seem not to be reliable on a SSD. I'm sure future versions will solve this issues.
The article doesn't exactly offer a way to securely erase the data, instead it offers the advice to encrypt it.

 

[Valentin N]

I haven't read the article but if someone wants to erase and make sure that the hard disk is unreadable, I would suggest that, that person takes an OS, like Ubuntu on a cd, select the partition and choose the SSD (I hope Ubuntu can erase data from SSD) and choose to format. When that is done take a hammer and hammer the SSD.

This is my tip :lolz: :666:

 

[bogdan]

That works too. But the challenge is to erase it without destroying it.

 

[Valentin N]

That works too. But the challenge is to erase it without destroying it.

It does and I get happy when I have the chance to hammer a HDD :lolz: but of what I know not even the secure standard erasing method for HDD is good enough... I know that Glary and CCleaner uses something in order to permanently delete files that are so called "erased".

 

[MetalShaun]

Doesn't the TRIM command get around this??

 

[LaserWraith]

Doesn't the TRIM command get around this??

Not quite sure:

Some SSDs get around to destroying things like old versions of files with garbage collection, and some can take care of deleted files with TRIM, but because an SSD's only immediate reaction to a deleted file is to forget where that file is rather than erasing it, files can sit scattered around an SSD for a while. Deleting files immediately would cause extra wear on an SSD, which is why they don't do it.

 

[bogdan]

I actually thought it does, too. At least according to this article on WindowsIT Pro. The real problem is that there is no standard telling manufacturers how to implement these functions and they do different implementations with the only scope to improve read/write speed that they can advertise.