4 ms·
On an SSD writing zeroes, may only trigger a remap of the NAND cells. There is a paper where data has been recovered under such situations... So writing zeroes
by rdc12 7y ago
On an SSD writing zeroes, may only trigger a remap of the NAND cells. There is a paper where data has been recovered under such situations... So writing zeroes hasn't been future proof for a decade or longer.
- wtallis 7y agoIn general, overwriting an LBA on a SSD will not cause a write to the same physical flash memory cells, no matter what the data pattern is. If you want to guarantee that the old version of the data is actually erased from the physical medium, you need to issue a drive sanitize command.
- rdc12 7y agoPretty sure people have discovered that is not reliable on some drives too, that it may only destroy the logical to physical map, and not change the actual data cells. It is surprisingly difficult to ensure deliberate data loss
- wtallis 7y ago> Pretty sure people have discovered that is not reliable on some drives too, that it may only destroy the logical to physical map, and not change the actual data cells. This can be the case for something like an ATA Secure Erase command, which is why the Sanitize commands were introduced to ATA, SCSI and NVMe. Those do explicitly mandate that all user data be erased, including from all caches and any storage media that is not normally accessible to the host system (ie. old blocks that haven't been garbage collected yet).