Secure erase necessary on a TRIM enabled OS?

[Carfax83]

Simple question, born out of curiosity. If I want to destroy all data on my SSD, do I need to do a secure erase, or will a simple reformat do the trick considering I am using Windows 8.1 which supports TRIM?

 

[Cerb]

TRIM is not sufficiently deterministic to be trusted for that. It might for one drive, but maybe not another. Go for a secure erase.

 

[razel]

Yes, only time I ever recommend a secure erase is prior to selling the drive to clear your data.

 

[Jovec]

I believe Secure Erase is the proper way to erase a SSD. They use internal encryption keys (separate from any user activated encryption) primarily for this purpose. The Secure Erase process will destroy the key and generate a new one, rendering all data stored with the old key inaccessible.

 

[phis6]

TRIM is not sufficiently deterministic to be trusted for that. It might for one drive, but maybe not another. Go for a secure erase.

I definitely agree, Secure Erase is a much safer procedure.

 

[Carfax83]

OK thanks guys, curiosity sated :thumbsup:

Reason why I asked was I read this article in which the author laments the downside of the TRIM command, by which he claims data recovery is essentially impossible once a file has been deleted and the command issued; even via forensics equipment.

So if you accidentally delete an important file and the OS issues the TRIM command, you're screwed! There's no way you're getting it back..

 

[Cerb]

But, there's no guarantee that every block will be properly marked as erased in some given time frame, nor what may happen if the SSD shuts down before it processes them all. TRIM, as implemented, does work, but is a way of telling the SSD that the block(s) in question can and should be erased, not an imperative that they must be erased right now (from the user's perspective, anyway).

On the other side of that unundelete issue with TRIM is that if you delete a file, but then shut down, it might not get TRIMed, unless a full free space map pass is done, and even then the SSD might need some time to process it all.

 

[Carfax83]

But, there's no guarantee that every block will be properly marked as erased in some given time frame, nor what may happen if the SSD shuts down before it processes them all. TRIM, as implemented, does work, but is a way of telling the SSD that the block(s) in question can and should be erased, not an imperative that they must be erased right now (from the user's perspective, anyway).

How often (or how quickly) an SSD does garbage collection is dependent on the particular model right?

Mine is a Samsung 840 Evo 1TB. I've read that the Evo models have a triple core SSD controller, so they can allocate one core for each operation including reads, writes and garbage collection..

So with that said, does that mean that the Evo models have real time garbage collection?

 

[Z15CAM]

Unless you have Illegal Content and under surveillance , Secure Erase is Hypo-Crap. Just busting the partitions is good enough when transferring media to another platform.

If your really concerned about data being accessed of your old media, Bust partitons and run something like Spin-Rite or nuke the media in a Microwave - LOL.

 

[WhoBeDaPlaya]

OP, just fire up Gparted Live and issue the following commands. Takes less than 5 mins total (for an SSD anyway)

sudo hdparm --security-user u --security-set-pass Poop /dev/sda ***
sudo hdparm --security-user u --security-erase Poop /dev/sda ***


If you run into problems :
sudo hdparm -I /dev/sda ***
and see if the drive is "frozen" or "not frozen". If it's "frozen", unplug and hotplug it (or put your system to sleep and resume).


*** Replace "sda" with whatever the SSD you want to erase is

 

[Z15CAM]

WhoBeDaPlaya - right on

For every day pounding to wipe out your sins on a live OS you can use something like MindWipe.

 

[mikeymikec]

I agree with Cerb - unless you had a utility that is designed specifically with SSDs in mind (and is known to work), I think with the abstraction going on with what the OS thinks is on the drive and what the SSD knows is on it, any other secure wipe utility (or 'thorough format', etc) doesn't stand a reasonable chance of hitting every sector of the drive.

I wonder if using some sort of 'zip bomb' type method might work better - creating a file that fills the entire drive with random data. Rinse and repeat until you think you're happy.

 

[Coup27]

Although only loosely related to the subject, TRIM or format does not remove the partition style from the SSD either. When I got my Win7 retail DVD, I experimented a bit installing with a traditional MBR partition style and with a GPT partition style. When simply formatting the disk or deleting all of the partitions so it was all unallocated space, the partition style remained on the disk. If I wanted to go back to MBR from GPT, I had to secure erase the SSD.