How to wipe a hard drive?
January 17, 2022 5:49 PM Subscribe
I am selling a few old external hard drives on Kijiji. What's the best way for me to completely wipe the hard drives so that any data I had on them is completely irretrievable by whoever purchases them?
CCleaner is a Windows utility. It has a free version, and it includes a drive wiper feature.
posted by alex1965 at 6:07 PM on January 17, 2022 [3 favorites]
posted by alex1965 at 6:07 PM on January 17, 2022 [3 favorites]
On a Mac, you can use the "Secure Erase" feature to create a new blank partition overwriting an old disk after several wipes.
posted by nickggully at 6:12 PM on January 17, 2022
posted by nickggully at 6:12 PM on January 17, 2022
Response by poster: I should have specified, I'm on Windows 10
posted by NoneOfTheAbove at 6:18 PM on January 17, 2022
posted by NoneOfTheAbove at 6:18 PM on January 17, 2022
On a windows 10 command prompt, you can also pass the format command a number of passes:
C:\> Format f: /P:4
posted by nickggully at 6:40 PM on January 17, 2022 [1 favorite]
C:\> Format f: /P:4
posted by nickggully at 6:40 PM on January 17, 2022 [1 favorite]
To answer this with confidence I'd want to be sure whether the externals were rotational/spindle drives or SSD-based. The above suggestions for multi-pass erases are good for rotational drives; SSDs do not benefit from multi-pass erases and instead use either an ATA command or encryption-based solution for secure erasure. Cheers!
posted by churl at 7:19 PM on January 17, 2022 [5 favorites]
posted by churl at 7:19 PM on January 17, 2022 [5 favorites]
If you don't have anything too sensitive on the drives, use the software suggestions above or perhaps a magnetic degausser.
If you do have anything sensitive on them, it's probably not worth the risk for what a used hard drive would sell for. I mean, brand new 2 TB drives are well under $100...
I believe the Canadian government's data security policy is that no software method can be trusted to definitively clear a drive — so instead entire hard drives and Blackberries go in a shredder to reduce them to sub-milimetre chips.
posted by sindark at 12:01 AM on January 18, 2022
If you do have anything sensitive on them, it's probably not worth the risk for what a used hard drive would sell for. I mean, brand new 2 TB drives are well under $100...
I believe the Canadian government's data security policy is that no software method can be trusted to definitively clear a drive — so instead entire hard drives and Blackberries go in a shredder to reduce them to sub-milimetre chips.
posted by sindark at 12:01 AM on January 18, 2022
Note that degaussing a hard drive will typically result in a non-working and therefore non-saleable drive. If you want to sell them, then overwriting the drive with random data multiple times (as noted in other answers) is the best bet against typical threats as this should be enough to render any data unreadable to the vast majority (if not all) of commercial drive recovery outfits.
If you need to protect against nation-state level threats then I'd agree that destruction is your best option.
posted by Aleyn at 12:18 AM on January 18, 2022 [2 favorites]
If you need to protect against nation-state level threats then I'd agree that destruction is your best option.
posted by Aleyn at 12:18 AM on January 18, 2022 [2 favorites]
DBAN.
posted by Geckwoistmeinauto at 4:09 AM on January 18, 2022 [1 favorite]
posted by Geckwoistmeinauto at 4:09 AM on January 18, 2022 [1 favorite]
Another vote for DBAN. You’ll need a small usb stick which will contain the program. You can format and reuse the stick after you’re done.
I’d recommend the “quick” option within DBAN as being more than suitable (there are other more paranoid ones, but they take longer) and you might want to consider starting the process before you go to bed.
posted by mr_silver at 9:20 AM on January 18, 2022
I’d recommend the “quick” option within DBAN as being more than suitable (there are other more paranoid ones, but they take longer) and you might want to consider starting the process before you go to bed.
posted by mr_silver at 9:20 AM on January 18, 2022
This thread is closed to new comments.
wipe -q /dev/sdxCarefully replace
sdxwith the device you're erasing. The q flag is for "quick," which only overwrites the drive with 4 passes of random data, speeding the process on large drives. To me this seems plenty secure for garden-variety paranoia, but you can draw your own conclusions.posted by pullayup at 6:01 PM on January 17, 2022 [2 favorites]