On 11/6/21 12:31 pm, David Wright wrote:
I'm about to install buster or bullseye on a newly acquired laptop with an SSD (a first for me). I'm intending to clean (zero or randomise) the entire drive with dd before I start, and am interested in any pitfalls with that.I will also encrypt the new /home partition, but for the remaining partitions I need to decide whether to add mount's discard option, or use a weekly systemd trim, or leave it entirely up to the garbage collection in the SSD device itself (which is an nvme THNSN5512GPUK TOSHIBA, presumably an OEM model supplied for this HP Spectre). The machine has 16GB of memory, so I wasn't intending to use swap. (It won't have to hibernate, and if push came to shove, there's always the possibility of setting up a swapfile or a ramdisk.) Background: The July 2017 system was pre-installed with Windows 10. I have copied the entire disk to external spinning rust, and can mount partitions from this image. It's difficult to foresee my ever wanting to reload and run this Windows system. The drive has unencrypted information on it, either in existing files, or in deleted/overwritten/whatever ones (though I think that is irrelevant to the method for erasing them). I don't work for the CIA, so "basic" erasure methods are sufficient, ie so-called logical and digital sanitisation, but not analogue sanitisation/purging. I'm just encrypting stuff like personal bank records etc, and not looking for anything like plausible deniability. Cheers, David.
The problem with SSD is that it's actually very difficult if not impossible.to completely erase them with DD. The drives have a large number of sectors in reserve and use them to wear level. This means some sectors may be swapped out when you do the DD and so aren't cleared.
There are some drives that have a self erase function that may work for your drive
See https://grok.lsu.edu/article.aspx?articleid=16716 -- Jeremy
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