• Appoxo@lemmy.dbzer0.com
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    1 day ago

    Fully overwriting an SSD is so archaic.

    Example from hdparm:

    --trim-sector-range
    For Solid State Drives (SSDs). EXCEPTIONALLY DANGEROUS. DO NOT USE THIS OPTION!! Tells the drive firmware to discard unneeded data sectors, destroying any data that may have been present within them. This makes those sectors available for immediate use by the firmware's garbage collection mechanism, to improve scheduling for wear-leveling of the flash media. This option expects one or more sector range pairs immediately after the option: an LBA starting address, a colon, and a sector count (max 65535), with no intervening spaces. EXCEPTIONALLY DANGER‐ OUS. DO NOT USE THIS OPTION!!

    I think the all caps warnings say it all.
    This is only for the trim sectors of the disk but I can’t imagine it being much different overwriting a whole disk.
    Not to mention, as OP said, an old and very used disk.
    Quick formatting should be enough to prevent any normal user from extracting meaningful data from the flash storage as only the controller knows how to piece together the flash cells to a file.
    If the controller forgets it, the files are toast anyway.
    At best write some random data to a quarter of the disk or something lile that.

    File recovery may only be possible if you give it to a drive recovery facility. But remember: Those ain’t exactly cheap.
    A client paid some 4 figure price because an HDD died. Just for a small amount of files.

    • WhyJiffie@sh.itjust.works
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      22 hours ago

      @[email protected] did a SecureErase, which is an entirely different function. It was exactly made to be used in this scenario: user is selling their laptop.

      other than that, hdparm --trim-sector-range is most probably only marked dangerous because with a slight miscalculation you can wipe some of your data and you won’t even know how much damage you did. I’m pretty sure the fstrim command relies on this, which is executed every few weeks on my system, by default. check systemctl status fstrim.timer, maybe on yours too.

      Quick formatting should be enough to prevent any normal user from extracting meaningful data from the flash storage as only the controller knows how to piece together the flash cells to a file.

      what do you mean by quick formatting? how do you do that on linux? I have only heard this term with te windows disk management tool.

      on windows quick formatting only deletes the partition entry from the partition table. that’s why it’s quick. all the former data is there and can be easily recovered, given you know the former partition boundaries, which can also be recovered by tools. the ssd controller won’t know a thing, it won’t forget where it should look for each LBA address.