"Basically...A Computer Stores Everything It Knows Since Day One"
I heard this quote from someone on the discovery channel... is this true? How does someone get qualifications and training to learn how to get absolutely all of these "nonexistent files" out of a computer? This boggles me.
Maybe you have to know how to write programs.
Pssshhh amazing.
Maybe you have to know how to write programs.
Pssshhh amazing.
Comments
Originally posted by Scott
Why am I bothering with all these backups?
Because although the files remain, the pointers to them are lost.
And yes, a computer does hold all the previous files on the harddrive unless you 0 it out. The pointers are removed, and data is just written over the old data.
Even if you were able to extract the old data, it could be severely fragmented with massive chunks missing.
That is the difference between a quick format and a full format. A quick format deletes all the pointers so the OS (or firmware depending on device) just writes over all of it as it fills up the drive.
If you do a full format (NOT the default in OS X but is in Win XP) you are effectively erasing the stuff. Now there are companies you see advertising in the back of some computer magazines who charge an arm and a leg but can restore the files...ususally
Originally posted by HHogan
Because although the files remain, the pointers to them are lost.
And yes, a computer does hold all the previous files on the harddrive unless you 0 it out. The pointers are removed, and data is just written over the old data.
Even if you were able to extract the old data, it could be severely fragmented with massive chunks missing.
I was trying to make a joke there.
Originally posted by Jwink3101
I believe that with OS X, if you do the secure delete of the trash then those file are written over and "zereoed." If you just delete, (as someone called them) the pointers are gone.
That is the difference between a quick format and a full format. A quick format deletes all the pointers so the OS (or firmware depending on device) just writes over all of it as it fills up the drive.
If you do a full format (NOT the default in OS X but is in Win XP) you are effectively erasing the stuff. Now there are companies you see advertising in the back of some computer magazines who charge an arm and a leg but can restore the files...ususally
Mac OS X has a secure but slow formatting option called "8-way random write format". When combined with the "zero all data" option, it'll make any data that was on the drive unrecoverable. Both options put together make the formatting process take a LONG time to complete. I tried it with an 80 GB drive, came back 4 hours later, and it STILL hadn't finished, so I aborted it and did a regular format.
Originally posted by iShawn
I heard this quote from someone on the discovery channel... is this true? How does someone get qualifications and training to learn how to get absolutely all of these "nonexistent files" out of a computer? This boggles me.
Maybe you have to know how to write programs.
Pssshhh amazing.
Exactly the same as the human brain... and just as irrelevant at a certain point as data overwrites (unless you have infinite storage, most of this becomes unrecoverable).
Sherlock Holmes once similarly said:
"The Brain is like an attic with finite space... in order to add more stuff, eventually you have to throw stuff out"
Incorrect claim for each formatting (as noted above), and the 'computer' has no long term memory of 'data since birth' if you swap out drives or repartition them or run them with little or no swap space at max capacity so overwriting is inevitable.
True in some instances, but an overstatement in others.
There are cases of large drives without such formatting where you can go back and recover the info of past users, but more modern systems are less likely to maintain a perfect forensic history back to the days they first learned to sing Daisy.
As for how one learns how to recover this info, if you're running a non-'nix OS, you can run a recovery or undelete software and see what it finds and claims to be able to reconstruct from lost FAT table pointers... or pay bags of cash to a company that specializes in costly data rescue.
Just so we all remember, that's a fictional character...so really, it's attributable to Sir Arthur Conan Doyle.
Originally posted by pyriX
completly off the topic, but curious suburb, Isaac Asimov is spelt with two a's not two s's
Dunno how I missed it so long... fixed... by one without two s's too.