> You have a good point with the bad blocks. But just writing to all the free space on the disk should cover the wear leveling issue.
I don't think you have a good mental model of how a SSD works. let me try and help.
Say you buy a SSD with 100 GB of space. It is really a 110 GB or 120 GB drive. You can only use 100 GB of it. During use, the drive will often "see" a bad sector, and remap it on the fly to one of the spare sectors it has on the device. When doing this - it does not wipe or do anything fancy to that "Bad" sector. So over time, small chunks of data get left behind in "Bad" sectors. You can format every single byte of visible space, but that will not touch "bad" sectors. Your format would only hit the 100 GB of space, it would totally ignore the 10 or 20 GB of spare or bad capacity.
So if someone gets your freshly wiped SSD, they can dig up all of the bad sectors and see what is there. Maybe nothing, maybe a part of a file that has your production credentials. The police and NSA have tools to do this fairly automatically. I suspect organized crime would as well.
Just writing some 0s to a SSD is NOT a safe way to wipe it.
I don't think you have a good mental model of how a SSD works. let me try and help.
Say you buy a SSD with 100 GB of space. It is really a 110 GB or 120 GB drive. You can only use 100 GB of it. During use, the drive will often "see" a bad sector, and remap it on the fly to one of the spare sectors it has on the device. When doing this - it does not wipe or do anything fancy to that "Bad" sector. So over time, small chunks of data get left behind in "Bad" sectors. You can format every single byte of visible space, but that will not touch "bad" sectors. Your format would only hit the 100 GB of space, it would totally ignore the 10 or 20 GB of spare or bad capacity.
So if someone gets your freshly wiped SSD, they can dig up all of the bad sectors and see what is there. Maybe nothing, maybe a part of a file that has your production credentials. The police and NSA have tools to do this fairly automatically. I suspect organized crime would as well.
Just writing some 0s to a SSD is NOT a safe way to wipe it.