Wiping Hard-Drive..

[EarlofCroydon]

Sold my iMac through eBay and need to wipe the hard drive.
Bit worried it will cause issues and also does a hard drive wipe
delete applications? As I would like to leave some on there...
also. How to do it?

Thanks

 

[simsaladimbamba]

Delete everything you want of this iMac, including your user (from another admin account), then go to Disk utility and select ERASE FREE SPACE.

 

[biggd]

Sold my iMac through eBay and need to wipe the hard drive.
Bit worried it will cause issues and also does a hard drive wipe
delete applications? As I would like to leave some on there...
also. How to do it?

Thanks

Putting the disk in, reformating and reinstalling is the best bet.
You clear all your data, you free up HDD space, and you'll speed up the iMac. If you wish you could re-install apps for your buyer after.

 

[chris98vf]

ok, here's the deal, ignore everything above and do exactly this...
Insert your install DVD and go to the Disk Utility when the install screen comes up. It's on one of the drop down menus up top.
Now that you have Disk util open select your hdd and click the format tab.
Format it using the security settings for a 7 pass format. Doing so will wipe your drive block by block not only once but 6 more times after. This is the same standard the DOD uses.
Not doing so will basically leave all of your data intact for anyone with slight curiosity to see every picture, video, email, document, ect... and all they need is an app they can download in 3 minutes.
I cannot stress this enough, format the drive properly and you'll be safe. If you want the added protection of ridiculous redundancy run the 35 pass format. Just so you know on average it takes 45 minutes per pass depending on the size of your drive so a 7 pass will take roughly just under 6 hours.

KEEP THOSE PICS OF THE WIFE TO YOURSELF

 

[simsaladimbamba]

ok, here's the deal, ignore everything above and do exactly this...
Insert your install DVD and go to the Disk Utility when the install screen comes up. It's on one of the drop down menus up top.
Now that you have Disk util open select your hdd and click the format tab.
Format it using the security settings for a 7 pass format. Doing so will wipe your drive block by block not only once but 6 more times after. This is the same standard the DOD uses.
Not doing so will basically leave all of your data intact for anyone with slight curiosity to see every picture, video, email, document, ect... and all they need is an app they can download in 3 minutes.
I cannot stress this enough, format the drive properly and you'll be safe. If you want the added protection of ridiculous redundancy run the 35 pass format. Just so you know on average it takes 45 minutes per pass depending on the size of your drive so a 7 pass will take roughly just under 6 hours.

KEEP THOSE PICS OF THE WIFE TO YOURSELF

So the posts of biggd and me are not valid?

Btw, ZEROING OUT is enough, as even that can't be restored with software one can find in 33 minutes.
DiskWiping – One Pass is Enough

Assuming the average WRITE speed during this 7-pass erase is 52MB/s (just tested it), then the 7-pass erase can erase 137GB in 45 minutes.

 

[chris98vf]

So the posts of biggd and me are not valid?

Btw, ZEROING OUT is enough, as even that can't be restored with software one can find in 33 minutes.
DiskWiping – One Pass is Enough

Assuming the average WRITE speed during this 7-pass erase is 52MB/s (just tested it), then the 7-pass erase can erase 137GB in 45 minutes.

If you have the right software, which isn't hard to find, you can recover data. How do you think pedo's get caught?
I have formatted many 160GB hdd's and one pass using the utility takes about 45 minutes.
Take this advice from someone who has actually recovered and destroyed data, USE MULTI PASSES!

 

[simsaladimbamba]

If you have the right software, which isn't hard to find, you can recover data. How do you think pedo's get caught?
I have formatted many 160GB hdd's and one pass using the utility takes about 45 minutes.
Take this advice from someone who has actually recovered and destroyed data, USE MULTI PASSES!

So does that mean, writing zeroes onto a HDD once does not delete anything?
There seems to be conflicting positions about this:

Guys, as a DoD employee and a computer forensics investigator, here is the lowdown... NOBODY has been able to recover any usable data from a drive that has even been single pass wiped. The DoD used to abide by the 3Pass wipe standard but has now adopted 7 pass. I've taken my GIAC certification and even in these classes NOBODY has been able to recover after a single pass has been made. The only reason why the DoD uses 7 is "in the event of future technological advancements", perhaps someone can figure it out years into the future. But for personal data, I would say that a single pass is going to pack enough stopping power for anyone that has the tools to recover deleted files. If you're trying to protect yourself because you've got something illegal on the drive, then ummm you should go ahead with the paranoid 35Pass. It will take a really long time, probably more than a full day at the least.

Oh yeah and if you keep the drive and decide to physically destroy it later...Well make sure you take it apart fully and scrape the platters down real good with a sander or wire brush. Some data recovery firms have been able to recover data off platter FRAGMENTS that were blown apart from an IED attack. Amazing technology out there.

Since 2001, all IDE & SATA HDDs have a built-in data destroy command called Secure Erase, to wipe the entire drive in one pass. It'll even wipe areas on the disk marked off limits (like bad sectors) to the OS and is more effective than multiple passes by software.

I don't know of a Mac utility to access the drive's erase command, but there's a Windows & Linux program. You can try to boot using the 'Ultimate Boot CD' as it comes with HHDErase to activate the drive's secure erase function.

Using data recovery software, I've found that one pass of Secure Erase to be more effective than multiple passes of a software wipe. I was able to find "some" data from the software wipe, and absolutely no data using the HDDs built-in data erase function. Secure Erase also wipes "between" the data tracks for a more effective wipe.

Info on Secure Erase

Ultimate Boot CD

from Best way to securely erase my entire MBP HDD?

 

[Meyvn]

Are you really worried "some guy that bought your computer on eBay" is after your old porn collection? If not, basically do what simsaladim says.

Though first, you'll want to go into Accounts under System Prefs & create a new Administrator-level account so you can delete that other one from it.

Complete erases like the other folks are talking about will wipe the apps you're trying to give the new person, so you'd have to reinstall all that pirated software you promised 'em.

 

[chris98vf]

very good info, btw... I used the 35 pass when selling my personal iMac. Nothing illegal but there's no way I want anything of mine out there just in case. Just for piece of mind I would still go with at least the 7 pass and if you're so inclined get the Ultimate Boot CD and go nutz.

 

[skiltrip]

The way I see it, there's no harm in the 7-pass "just to be safe". Start it before you go to bed. It'll be done waiting for you in the morning. No need to make a big hoo-ha about the whole thing, or god forbid, sit and watch it while it's doing the 7 Pass Shuffle.

 

[300D]

A 7 pass is a complete waste of time. A single pass will destroy data beyond the point even professional forensics companies can recover.