how to check SSD usage and secure erase via USB

[clifftam]

Hi everyone,

I got a Samsung EVO 850 that I like to wipe out all the info and check the SSD usage. How do I do it via USB?

I read online that you can't do it with Samsung Magician because it only accesses SSDs that are connected internally.

Is there any free software that I can use?

 

[InvalidError]

Magician (and other software) cannot do a secure SSD erase because storage devices attached to USB only have access to the generic block device interface, not the full ATAPI required to access low-level vendor-specific functions required for secure block-erase.

The next best thing you can do is use a "shredder" program to overwrite the whole device which will at least guarantee that this much of the underlying raw storage capacity got overwritten. Due to write-leveling re-mapping pages as they get re-written, it isn't possible to guarantee that 100% of the device got overwritten without low-level access.

 

[USAFRet]

1. Why are you wanting to do this? Is this a used drive that you just got?

2. Try it. See if it works in the Samsung Magician.
If it does not, then we can explore other options.

 

[mazboy]

I have been told--by people who are supposed to know these things (although I've never had it confirmed by an absolute authority)--that if you take an SSD, delete the partitions, repartition it and the format it, you have rendered the former data unreadable. This has to do with the way an SSD keys track of data location. If I'm wrong tell me, but tell me why, too...

 

[USAFRet]

I have been told--by people who are supposed to know these things (although I've never had it confirmed by an absolute authority)--that if you take an SSD, delete the partitions, repartition it and the format it, you have rendered the former data unreadable. This has to do with the way an SSD keys track of data location. If I'm wrong tell me, but tell me why, too...

Yes, that's pretty much correct.

 

[InvalidError]

If you did a "quick format" then a fair chunk of the data can still be recovered by creating an uninitialized blank file the size of all accessible space or doing raw block reads. The block order will be all messed up due to the translation table between the old logical map and the physical media being different with some of it overwritten by the new file system structures or hidden by the write-leveling map but that may still be enough to recover some usable unencrypted data.

 

[canadianvice]

I have been told--by people who are supposed to know these things (although I've never had it confirmed by an absolute authority)--that if you take an SSD, delete the partitions, repartition it and the format it, you have rendered the former data unreadable. This has to do with the way an SSD keys track of data location. If I'm wrong tell me, but tell me why, too...

You're basically not wrong for all practical purposes. However, it is still technically recoverable by a VERY determined party. Put it this way. You wipe a normie HDD? You come to your repair shop, we charge you $200 or w/e to get your data back, we almost certainly do, and you leave happy, -$200.

Bring in an SSD? $5000+ and it's a crapshoot. It can happen, but it's damn hard and VERY expensive. Anyone you wouldn't want getting that data can't realistically get it, and anyone who still wants it has resources you can't really fight anyway.

 

[USAFRet]

And still we've not heard back from the OP as to "why".

 

[InvalidError]

Bring in an SSD? $5000+ and it's a crapshoot. It can happen, but it's damn hard and VERY expensive. Anyone you wouldn't want getting that data can't realistically get it

Doing an exhaustive search of the raw blocks is well within the means of anyone, you only need to know exactly what you are looking for and be lucky enough to find it located in the same block as easily identifiable data. Ex.: search for "mastercard", "visa", "amex", etc. and you may be lucky enough to find that in the same storage blocks as names, card numbers and expiry dates as consecutive columns in a spreadsheet, text file, database, etc.

For data larger than a single block like photos and videos though, not having the original data's physical-logical address map does render reconstruction extremely tedious at best.

After a full-format though, recovery is practically impossible in both cases. The SSD may still leak info from spare pages that haven't been overwritten by the full-format.