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Is it safe to wipe free space and sell the iMac

Trogledyte Mac

Trogledyte Mac

macrumors regular
Original poster
Oct 15, 2006
129
2
Hi all,

I have a iMac 27, early 2013.
The graphics/video card is broken and gives me a startup-screen with some little stripes and the startup goes no further than the logo and stops halfway the startup indicator.
No problem because I have a buyer for this iMac, but I can only access the 1T SSD via a thunderbolt-cable and my Mac book...
A format seems not possible via thunderbolt?
So I deleted all the important and privacy files and then next I did a wipe free space x7 with Shredit x..... Next I deleted the last files and did again a wipe free space x3 with Shredit x. So the SSD seems all empty now and the iMac gives a question mark at startup... No problem for the buyer!

But is it safe now to sell my iMac and are my privacy files now destroyed?

Kind regards,
 
Yes, you can format via Target Disk Mode.

Then iMac is simply an external drive; fire up Disk Utility and wipe it. Sounds like that's where you were at. Disk Utility should see and be able to erase or partition the external (to the host laptop) drive.

If for some reason you don't want to or can't....deleting all user home directories will ensure no personal data is left.
 
Hi hobowankenobi,

Starting up in target mode was no problem but via disk utility it was not possible to format the drive, I got always the error that say 'no permission' to.... the same for BCwipe, I was not allowed to format only rename that works...
So is my data destroyed now and is it safe to sell the iMac.
 
Are you sure it's 1TB SSD? Maybe it's 1TB Fusion. That would explain why you are having difficulties formatting it via Target Mode.

If it's a single drive (not Fusion) then Target Disk mode should be able to format the drive.

In Disk Utility / View, make sure 'Show all Devices" is selected. Sometimes it turns itself off, then you see only the partitions, not the actual container drives. You need to format the drives, not the partitions.
 
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Trogledyte Mac said:
Hi hobowankenobi,

Starting up in target mode was no problem but via disk utility it was not possible to format the drive, I got always the error that say 'no permission' to.... the same for BCwipe, I was not allowed to format only rename that works...
So is my data destroyed now and is it safe to sell the iMac.
Click to expand...


Sounds like your data has been removed....assuming you found all of your data. The challenge is being sure you got everything. Deleting all the home directories would delete all unique user data, and render the machines fairly useless (with no admin account). All that would be left typically is some installed application, but not user data or documents....unless you kept user documents in some unrecommended spot...like the Applications folder.

That should be fine, assuming the new buyer will be installing a fresh OS on it anyway.

Per RedTomato, there should be nothing on a standard setup that would prevent you from erasing the attached drive. All you should need is the mounted TDM machine, and admin credentials on the host machine.

If that STILL doesn't work, you could boot to Internet Recovery mode and run Disk Utility from there. All you need is a network connection. As a bonus to the new user—And the peace of mind for yourself—you could format the drive, and install a fresh OS all from internet recovery. Then there is no question that anything was left behind that could be recovered later.
 
Hi all,
thx for your answers and help.

@ redtomato
And yes it is a 1TB Fusion drive..
My mistake, I was confused because Shredit x was always saying and I quote,
"This item is on an SSD. Overwriting individual items on SSD, due to the physical design of SSD, may not work. You should trash the item, empty the trash, and then shred the disk free space, which does work on SSD, instead"

@ hobowankenobi,
Because I can only use the Target disk mode for accessing the fusion drive of the broken iMac and it seems that I was not able to format the fusion drive... So I did the above, deleting first some folders with personal data , e-mail and some other stuff and shred the free space, I did this 2 times after a second controle and deleted some more files or folders and again I did a wipe free space.
And I did not use the Applications folder for personal user data.
Yesterday I deleted the rest of it and the iMac give now at startup that question mark what not a problem is for the buyer.

I just like to know is it safe now to sell... I getting out of time because the buyer want the iMac this evening.. Maybe I can push for one extra day... and this buyer gives me a very good price ;)

@ Guy Clark,
Thx I know but...
I was not able to do all this things like sign out of iCloud or erase and reinstall because I can not accessing directly the iMac only via Target disk mode with a thunderbolt cable for accessing the drive directly.

Now a friend of me says just now "fill the drive with some big files like movies or so.... and delete them when the drive is full that will do the trick" Work this?


Kind regards,

edited last info.
 
Last edited:
RedTomato said:
I think you'll be fine. Log into icloud.com and see if your iMac is listed there. If it is, remove it.
Click to expand...


Thx RedTomato :)
Yes I did that a few weeks ago via iTunes and checked later via iCloud.. it shows only what I use.
I was only not sure for several emails with some serials that I recently got just before the iMac was broken.
Feel me more safe now!


Kind regards,
 
I don't know what shredit x is, but..

if you want to secure your files you have to secure erase your drive at least once and I would prefer 3 times if its an HDD.

If its an SSD then, I heard that information can always be retrieved from those. Do what Apple says before selling a computer then encrypt the HDD. not sure if it will be usable after that.

to be honest, the best way to make sure your data is safe is take the hard-drive to a shredder . Of course delete everything first via secure erase.
 
MacBH928 said:
I don't know what shredit x is, but..
Click to expand...

"ShredIt X permanently deletes files from your hard disk. Deleted data can be recovered from your computer. Protect your privacy with this easy to use file shredder | hard drive cleaner for Mac OS X that will erase data so it can't be recovered. Whether you want to clean a disk or wipe disk free space, ShredIt for Mac OS X is the right security eraser software for the job. Secure Delete files, disk free space, a hard drive, an external drive, a CD-RW and more. It comes with simple instructions, built in safety features, DoD, DoE, NSA, Gutmann standards compliance and online tutorials."

http://mireth.com/shredit/shredit-x/
or via the App Store
 
can you use diskutil secureease method in Terminal of Target disk mode? That would be one way to do this if it worked. Just do one pass wipe only

MacBH928 said:
to be honest, the best way to make sure your data is safe is take the hard-drive to a shredder . Of course delete everything first via secure erase.
Click to expand...

I would think the physical shredder would be more than enough no ? any software side secure erase tool would be moot compared to physical destruction, particularly unless your in the need to reconstruct the physical pieces, which most most be able to even do, i would say the software side is over-kill
 
Tech198 said:
can you use diskutil secureease method in Terminal of Target disk mode? That would be one way to do this if it worked. Just do one pass wipe only



I would think the physical shredder would be more than enough no ? any software side secure erase tool would be moot compared to physical destruction, particularly unless your in the need to reconstruct the physical pieces, which most most be able to even do, i would say the software side is over-kill
Click to expand...


Oh no.

Must secure wipe first. You don't want somebody digging through your trash, and taping the shredded strips of your hard drive back together so they can steal your data...


:D:p:rolleyes:
 
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