caperjack said:
hard drives have multiple layers
What???
No they don't! They have multiple "platters" but those are not layers. And data is not saved in layers either.
,an good recovery tool will dig into these layers to find files ,so tour theory of fill the drive with music is not a good one in my opinion , when I want to make sure everything is gone I use a tool [from Microsoft ]that makes 2 or 3 passes and into those layers ,and takes all night to run.
No! I am sorry but you don't understand how hard drives work!
Filling a drive with music, photos, or any other type of files is just as effective at overwriting data as one pass with a wipe program. If you want more passes (which is a good idea to ensure every bit in every sector is touched at least once), just delete those files and fill the disk again with more music files and that is pass two. A wipe program does the same thing, only it is automated thus more convenient and the data saved is random, not a program (song, in this case). Photo or movies will work too.
I am NOT saying saving music files is better, just another effective option.
The idea behind a forensic analysis relies on the fact hard drives work by aligning magnetic particles on the platters in such a way they (the particles) represent a 1 or 0. Some "residual" magnetism of the previous data
may remain that
might be picked up by
very expensive specialized equipment when those drives are disassembled and the platters are removed from the drive. The drive's own R/W heads are
not sensitive enough or capable of detecting those super low-level residual magnetic fields, so the platters MUST be removed then analyzed individually by that very expensive, specialized equipment.
And the reason the drive's own R/W heads are not sensitive enough is
intentional! Otherwise, the R/W heads would pickup the magnetic fields ("the data") in the adjacent tracks and sectors instead of just the one sector is supposed to be reading.
So what is free space? If I completely fill my HDD capacity with all the music files I could probably get, then it would fill up the available "free-space" too automatically, isn't it?
Yes. Free space just means that space is available to save data in. If the drive is 1/2 full with Windows, Office, and your data files, then the rest of the disk space is "free". If you fill the rest of the drive with music files, there is no free space left and that would be the same as "one pass" with a wipe program as far as "overwriting" any previously saved (but "deleted") data. Remember, deleted files are not really deleted or erased, the space is just marked as free in the drive's allocation tables.
The only difference is with a wipe program, after the pass, the space is marked as available (free) again. When using music files, you would have to delete the files to free up the space.