How is it possible to partition a HDD without corrupting its contents? - eviltoast

A moment ago I unmounted my 1TB HDD with 400GB of content and I partition it into two different partitions, obviously keeping the space that was already occupied. I did because I don’t care if the content get corrupted, but after I did it everything is still working perfectly, when I thought everything would be corrupted.

I am possibly a complete ignorant on this subject, but due to the nature of the HDD and how it writes and reads data I expected it to corrupt everything, why didn’t it happen? On an SSD on the other hand I would not consider that possible because it is not even a mechanical part where the information is stored.

  • Spuddaccino@reddthat.com
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    1 year ago

    I think the idea comes from “HDD slow,” as he was impressed with the speed it was happening at, especially if you think of it as requiring data to be moved around on the disk. It’s not really intuitive to think of it as just a table on the disk somewhere that says which regions belong to which partition, and having those regions be anywhere on the disk.

    • ∟⊔⊤∦∣≶@lemmy.nz
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      1 year ago

      Is that actually how it works? I thought that was only within the partition itself, while partitions are physically separate on the platter.

      • Spuddaccino@reddthat.com
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        1 year ago

        For SSD’s, it’s 100% a logical table, because data is stored all over the place for load balancing purposes, so it already uses a logical table to keep track of what each block is for at any given point in time.

        For HDD’s, historically they were physically separated, and they mostly are still, but there’s still a logical table, and there’s no reason the logical table can’t say “Blocks 0 through 1234 and 2000 are part of partition 1” if you have something somewhere else that you want on that partition.