How does the hard drive erase data? - Techist - Tech Forum

Go Back   Techist - Tech Forum > Computer Hardware > Monitors, Printers and Peripherals
Closed Thread
Thread Tools Display Modes
Old 04-26-2004, 07:09 PM   #1 (permalink)
Super Techie
Join Date: Apr 2004
Posts: 268
Default How does the hard drive erase data?

subject explains my question, how does the hard drive erase data?

NanoWarrior is offline  
Old 04-26-2004, 07:16 PM   #2 (permalink)
HONK if you route packets
mikesgroovin's Avatar
Join Date: Sep 2003
Location: MD
Posts: 4,715

The harddrive won't erase data right away. If you are deleting a bunch of files from anywhere on your disk, the system tells the drive which files in which locations you are "removing". The drive will then goto it's table and remove the file's entry (or folder's entry) and remove it from the table. This way, the drive no longer "thinks" that the removed file is still on the drive. The files actually don't even move.....they are all still on the physical drive. The file(s) get removed (or over written) when you add an application or more files to replace the area on the drive where the other files physically were. Does this make sense?? Hope it helps.


mikesgroovin is offline  
Old 04-26-2004, 07:24 PM   #3 (permalink)
Ultra Techie
Join Date: Oct 2003
Posts: 504

A good way to think of it is like a book. All of your data is stored in "chapters" and their location is recorded in a "table of contents". When you delete something, the operating system erases the "chapter" or files location from the "table of contents". The chapter is still in the book, but it doesnt show it in the table of contents, or to the user. To actually erase the data though, you have to go and reformat the hard drive in which case the laser that reads and writes with will burn the layer of material smooth again and get out the notches that it created when you wrote data to the disk. The process is more complicated then that but for a general sense it just creates divots in the cd when you write to the disk and then smooths it back out when you erase the data.
<img src = \"\">
ThirtySixBelow is offline  
Old 04-26-2004, 07:40 PM   #4 (permalink)
HONK if you route packets
mikesgroovin's Avatar
Join Date: Sep 2003
Location: MD
Posts: 4,715

Thanks for the analogy....sometimes, when I'm in super-geek mode (like right now), I can't analyze and taper down a thought process that might be a little more easy on the eyes....

mikesgroovin is offline  
Old 04-26-2004, 07:54 PM   #5 (permalink)
Wizard Techie
Join Date: Jul 2003
Posts: 3,937

so what that means to you is even if you empty your recycle bin, you can use data recovery software to get that data back. to permanently erase data you use disk wiping software that wipes the entire hard disk, the free space, or just certain files. disk wiping takes a long time to do.
ekÆsine is offline  
Old 04-27-2004, 05:35 AM   #6 (permalink)
Monster Techie
Join Date: Jan 2004
Posts: 1,124

If you want to totally wipe the drive ( zero out the HD ) .
Go to the HD manufacture`s website and Download a Utility for the model you have .The Utility will create a Bootable Floppy . You can run several tests on the drive as well .
Thermaltake Armor A90
Corsair HX1000W PS
i7 2600k / Cooler Master Hyper N 520
Asus P8Z68-V Pro / Gen 3
8 GIG Corsair Vengeance
eVGA GTX 570
SB Audigy2 Platinum
Kingston Hyper X120 SSD
WIN 7 - 64b
LG Blue Ray Super Multi Burrner
Logitech THX Z560
3x120mm - 1x200 mm case fans
Cappy is offline  
Old 04-27-2004, 08:07 AM   #7 (permalink)
Techie Beyond Description
Apokalipse's Avatar
Join Date: Jun 2003
Location: Melbourne, Australia
Posts: 14,556

..... or you can chuck in your OS CD and do a full format (not quick)
Apokalipse is offline  
Old 04-27-2004, 09:09 AM   #8 (permalink)
Ultra Techie
Join Date: Jan 2004
Posts: 872

Originally posted by apokalipse
..... or you can chuck in your OS CD and do a full format (not quick)
...nope this won't help ..u can still recover data very easily if u do this...

What Cappy said was more appropriate ... Just lowlevel format the drive n' then zerofill it a couple of times.. the drive data is almost unrecoverable.
Screenshots of my Desktop.....Post ur\'s too :D

AMD AthlonXP3000+@ 2.2GHz, Cooler Master Aero 7+, Gigabyte 7NNXP , 1GB Kingston HyperX PC3200 Dual Channel , MSI FX5600 VTDR 256 ,Pinnacle PCTV , 120+120GB Barracuda , Liteon 52x CDRW , Samsung DVDROM , Benq DW1620 16x DVD ReWriter, Phillips 21\" TV,Samsung Syncmaster 763MB,Logitech Cordless MX DUO , Thermaltake Silent PurePower 480W Butterfly Series PSU, Win XP SP2,RH9.
Creative DDTS100 Decoder, Creative Inspire TD7700 7.1 Speakers

Search TF B4 u post { Thanks for this one! Emily :) }
<form action=\"\"><input type=\"text\" name=\"search\"><input type=\"submit\" name=\"submit\" value=\"Search!\"></form>
preet2u is offline  
Old 04-27-2004, 03:17 PM   #9 (permalink)
Wizard Techie
Join Date: Apr 2004
Posts: 3,247

a format only marks the area as useable and wipes out file info from the table. the info is still there, just marked as useable. so all those 1's and 0's haven't gone anywhere. so what you need to do is what was suggested above, and write zero's. that removes it all. instead of being marked as ready for use, it will take something like 0010 1101 etc and write it to 0000 0000... all the way through. be warned, though. you dont want to do this on an old drive (I'd say 10 years or so) since much of the HDD info is contained on it's own manufacturers partition and if you write zero's it wont know what it is. be a pain in the a$$ to fix. anyhow, for example there is first aid I think by western digital.

as was posted above, cd's are different than HDD. CD roms write and rewrite differently depending on the format. Old CDR used the burn approach. some of the later RW burners use similar approach except that there are metalic type dyes in cd itself. when the plastics melt the dyes are attracted (before the cooling sets) and are put into the groves created by the laser. yet another uses a beam to polorize special dyes in the cd under the clear coat. these do not 'BURN', but line the dyes up in a polor-nonpolorized or 'one=polor' 'zero=blank' and use the cd table to determine stop start bit and length. well, have written way to much and tend to jump around to the point where its not legible after awhile. so much crap in my head and no easy way to bring it out sometimes
If you argue with an idiot he will drag you down to his level and beat you with experience.

I am not a fast writer.
I am not a slow writer.
I am a half-fast writer.

-Robert Asprin
killians45 is offline  
Old 04-27-2004, 03:24 PM   #10 (permalink)
Newb Techie
Join Date: Apr 2004
Posts: 6

if ive formatted
(full format) my drive twice, should that be securer than once?

mjsmolko is offline  
Closed Thread

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 06:57 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.