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I know these things about storage devices:

  • They're separated into two parts: the file table and the file data
  • The way these work is dictated by the file system
  • All file systems have a file table and file data
  • The file table can be changed without changing the file data, and vice versa
  • A file can be removed from the file table for a quick delete without actually removing the file's data

So, my question is: when you change the file system on (or "format") a drive, why must all the file data be lost? Can't a computer simply remember the file table and re-create it in the format of the new system?

I'm sure you'd run into some issues with a completely full drive if the new file system requires a larger table than the old system, but other than that, I don't see why this can't be done.

I also know that after a "quick format" (where just the file table is replaced, but the new one is empty) that all the file data is still there and can be recovered with forensic tools.

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1 Answer 1

when you change the file system on (or "format") a drive, why must all the file data be lost?

It doesn't have to be. Normally formatting a drive is done to initialize a new drive with no data or discard the data that was on it.

Should you have a storage media with data on it you could easily change the file system structure from one to another (e.g. FAT -> ext3) in any number of ways. This is not done very often by end users nor in multi-user environments. The approach varies depending on details you did not provide. Note that not all your assumptions are necessarily valid.

To learn more about file systems checkout http://en.wikipedia.org/wiki/Filesystems.

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Cool! How would one go about doing so? –  Supuhstar Jun 24 at 17:03
I never have. I rarely change file systems on a device that is in use; if I had to then I would back-up the volume, change the file-system, and restore the volume. –  Ram Jun 24 at 22:36

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