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SSDs are not magic. For shredding to be impossible the drives would have to have hidden capacity (and a lot of it, more than 1%). People often say, write levell

SSDs are not magic. For shredding to be impossible the drives would have to have hidden capacity (and a lot of it, more than 1%). People often say, write levelling makes overwriting useless, but what if you overwrite the entire disk? How would you recover after something like this? Of course providing something like 10% of hidden extra capacity would extend the life of the drive significantly, but are manufacturers really doing that and are not mentioning it in their marketing materials? I never heard that they do that.

Grimburger 3y ago
Sure, but very few business tools are doing that, they are playing the old Gutmann game which he himself has walked away from as not reliable anymore. Filling up the drive is certainly getting you somewhere compared to some of the snake-oil out there. Drives are only getting bigger though and rarely filled up, done some of this stuff in my time and if cost is no barrier then you'd be surprised how much can be reclaimed. Degauss and destroy is the only real method we have now and that's probably not changing in future. >but are manufacturers really doing that and are not mentioning it in their marketing materials SSD manufacturers have been caught out repeatedly with their in-built deletion API claims. Recovery of a significant % of files is possible nearly always without tampering having occurred.
colechristensen 3y ago
> Of course providing something like 10% of hidden extra capacity would extend the life of the drive significantly, but are manufacturers really doing that and are not mentioning it in their marketing materials? I never heard that they do that. Every SSD has considerably more physical blocks than reported blocks. They have to, SSD bad blocks are common and number of writes is quite limited compared to hard disks. https://download.semiconductor.samsung.com/resources/others/Samsung_SSD_845DC_04_Over-provisioning.pdf https://download.semiconductor.samsung.com/resources/others/...
justinclift 3y ago
> I never heard that they do that. Not sure how you missed it, as it's not a new thing. Straight from the horses mouth, if that helps: :) https://www.kingston.com/en/blog/pc-performance/overprovisioning https://www.kingston.com/en/blog/pc-performance/overprovisio... Note that it's not just a Kingston thing, it's common across SSD manufacturers. Or at least with the major ones.
LoganDark 3y ago
SSDs don't cycle blocks based on how much you've written. You can write over the entire reported capacity of a drive 100 times and there's still the chance, however small, that your encryption key and some encrypted data are still sitting around on some chip. You just can't guarantee that it's gone. For all you know, the controller has marked them as bad and isn't going to reuse them, even though there's still recoverable data on them. Since there's no way to reach them through the drive interface, there's also no way to erase them. But if someone opened up the drive and pulled the chips, there they would be.
matheusmoreira 3y ago
> what if you overwrite the entire disk People who want secure deletion generally want their storage device to remain functional afterwards. Same reason they don't simply destroy the disk to get rid of its contents: those things are expensive. Overwriting the entire SSD every time you want a file gone just isn't a solution.

Grimburger 3y ago

Sure, but very few business tools are doing that, they are playing the old Gutmann game which he himself has walked away from as not reliable anymore. Filling up the drive is certainly getting you somewhere compared to some of the snake-oil out there. Drives are only getting bigger though and rarely filled up, done some of this stuff in my time and if cost is no barrier then you'd be surprised how much can be reclaimed. Degauss and destroy is the only real method we have now and that's probably not changing in future. >but are manufacturers really doing that and are not mentioning it in their marketing materials SSD manufacturers have been caught out repeatedly with their in-built deletion API claims. Recovery of a significant % of files is possible nearly always without tampering having occurred.

colechristensen 3y ago

> Of course providing something like 10% of hidden extra capacity would extend the life of the drive significantly, but are manufacturers really doing that and are not mentioning it in their marketing materials? I never heard that they do that. Every SSD has considerably more physical blocks than reported blocks. They have to, SSD bad blocks are common and number of writes is quite limited compared to hard disks. https://download.semiconductor.samsung.com/resources/others/Samsung_SSD_845DC_04_Over-provisioning.pdf https://download.semiconductor.samsung.com/resources/others/...

justinclift 3y ago

> I never heard that they do that. Not sure how you missed it, as it's not a new thing. Straight from the horses mouth, if that helps: :) https://www.kingston.com/en/blog/pc-performance/overprovisioning https://www.kingston.com/en/blog/pc-performance/overprovisio... Note that it's not just a Kingston thing, it's common across SSD manufacturers. Or at least with the major ones.

LoganDark 3y ago

SSDs don't cycle blocks based on how much you've written. You can write over the entire reported capacity of a drive 100 times and there's still the chance, however small, that your encryption key and some encrypted data are still sitting around on some chip. You just can't guarantee that it's gone. For all you know, the controller has marked them as bad and isn't going to reuse them, even though there's still recoverable data on them. Since there's no way to reach them through the drive interface, there's also no way to erase them. But if someone opened up the drive and pulled the chips, there they would be.

matheusmoreira 3y ago

> what if you overwrite the entire disk People who want secure deletion generally want their storage device to remain functional afterwards. Same reason they don't simply destroy the disk to get rid of its contents: those things are expensive. Overwriting the entire SSD every time you want a file gone just isn't a solution.