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golfgirlgolf

macrumors regular
Original poster
I'm doing some rearranging of backup drives and erasing those I don't need. The quickness of El Capitan's "Erase" indicated it wasn't really doing much for security other than wiping the top level directory - so I tried secure erase (no more option for what levels - 1pass, 7pass).

Unfortunately it's taking FOREVER, and DU will not allow us to Quit or Stop or Cancel the process - and will not Quit the program either. So all we're left with is to wait hours or even days for it to finish with no way to escape*. Unless someone here might know?

Of course *Activity Monitor could Force Quit - or maybe a restart - but the lack of any straightforward UI bail out in DU is totally bogus. :-(

Next time we'll have to do this on an idle computer and forget it for a day or so - per each drive.
 

Pndrgnsvc

macrumors 6502
Jun 13, 2008
452
26
Georgetown, Texas
You may care to try Permanent Eraser ( http://www.edenwaith.com/products/permanent eraser/ ). There is a preference to erase 1, 3, 7, or 35 times. I have been using it for a few years without issue. And it's free!

In your case: Launch Permanent Eraser, drop the BU drive on the PE icon in the dock, click OK, and voilà.

Should you do such, please post back as I'm interested in your results and thoughts/opinions.
 
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golfgirlgolf

macrumors regular
Original poster
You may care to try Permanent Eraser ( http://www.edenwaith.com/products/permanent eraser/ ). There is a preference to erase 1, 3, 7, or 35 times. I have been using it for a few years without issue. And it's free!

In your case: Launch Permanent Eraser, drop the BU drive on the PE icon in the dock, click OK, and voilà.

Should you do such, please post back as I'm interested in your results and thoughts/opinions.

Thanks - I did try it, but it's a little scary in that it doesn't even show the name/ID of the item your about to erase. Of course you know what that is by dropping the drive on the icon but the lack of a confirmation of exactly what you're doing is more than enough to cause doubt. I'll probably have to stick with Disk Utility for now, and do it as a dedicated task on a MacBook or something - just to be on the safe side.

What make and model is the drive, and how is it connected?

I have several - various makes - but all USB 2.0 via an active USB 3.0 hub for ease of plugging/unplugging one at a time as they go through the cleaning process.
 
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simonsi

Contributor
Jan 3, 2014
4,851
735
Auckland
To be honest if you are disposing of the drives and want no issues, ever, then just put a hammer to them and physically destroy them.
 

Pndrgnsvc

macrumors 6502
Jun 13, 2008
452
26
Georgetown, Texas
Thanks - I did try it, but it's a little scary in that it doesn't even show the name/ID of the item your about to erase. Of course you know what that is by dropping the drive on the icon but the lack of a confirmation of exactly what you're doing is more than enough to cause doubt. I'll probably have to stick with Disk Utility for now, and do it as a dedicated task on a MacBook or something - just to be on the safe side.

That makes sense to me. Just because it seems it would work, well, we have all been bitten by that bug...

Much could depend on the type drive/volume, size, etc. All kinds of things could cause PE to choke. I just thought that since you wanted the drive wiped, there was little chance of damage. But of course, better safe than sorry and being cozy with your decisions/actions is always wise.
 

grahamperrin

macrumors 601
Jun 8, 2007
4,942
648
… an idle computer …

… to erase a drive with moderate/light security that is FASTER than 1 day/TB?

If you do have a spare/idle computer, I highly recommend UBCD (mentioned in the earlier topic) with Parted Magic, HDAT2 and so on. Reasonably prominent after booting Parted Magic you'll find a utility that can work with a feature that's integral to some drives; I can't recall the name of the feature but basically the the intelligence to perform a secure erase is integral to the drive. Whether you'll be able to access that feature over USB, I don't know.
 

Erdbeertorte

Suspended
May 20, 2015
1,180
500
Would it be secure to just format them encrypted and then unencrypted again if they would be used by someone else after that?

I had some old hard drives that were just too small to sell or give them away. I just formatted them to a different file system and after that to HFS+ encrypted with a very long password and just threw them away. But there wasn't any sensitive data on them.

For drives that have all my data on them and got damaged in some way I always open them with a screwdriver and destroy the disks physically by scratching them very deep or even breaking them into pieces. ;) Also if they are encrypted.
 
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grahamperrin

macrumors 601
Jun 8, 2007
4,942
648
… just encrypt …

Would it be secure to just format them encrypted and then unencrypted …

If a Core Storage logical volume is encrypted at the time of creation: that alone does not encrypt all bits of the volume. The creation takes no more than a few moments.

If a non-encrypted volume is converted to use encryptionand if that conversion is allowed time to complete – then all bits are 'taken care of'.
 
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Mr. Retrofire

macrumors 603
Mar 2, 2010
5,064
519
www.emiliana.cl/en
OK if no one has an answer to this - how about an alternative way to erase a drive with moderate/light security that is FASTER than 1 day/TB?
In a terminal window type:
Code:
diskutil list

which gives you a list of mounted volumes and a list of device paths.

Code:
/dev/disk0 (internal, physical):

  #:                       TYPE NAME                    SIZE       IDENTIFIER

  0:      GUID_partition_scheme                        *256.1 GB   disk0

  1:                        EFI EFI                     209.7 MB   disk0s1

  2:                  Apple_HFS Apple SSD               255.2 GB   disk0s2

  3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3

/dev/disk1 (external, physical):

  #:                       TYPE NAME                    SIZE       IDENTIFIER

  0:      GUID_partition_scheme                        *2.0 TB     disk1

  1:                        EFI EFI                     209.7 MB   disk1s1

  2:                  Apple_HFS Backup                     2.0 TB     disk1s2

This command overwrites the device "theDevicePath" (including any and all partitions ) with zeroes:
Code:
sudo diskutil secureErase 0 theDevicePath
(replace "theDevicePath" with the actual device path-see below)

The full command line to overwrite the device which contains the "Backup" partition (see above) is:
Code:
sudo diskutil secureErase 0 /dev/disk1

See also:
https://developer.apple.com/legacy/...arwin/Reference/ManPages/man8/diskutil.8.html
 
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golfgirlgolf

macrumors regular
Original poster
Thanks all for some very good answers - the drives (1TB, 1.5, 2TB) are to be sold/given out - so they need to be cleaned - not destroyed. They are like new (only used for long term storage/backups and hardly spun up, ever). 5TB drives didn't exist or weren't affordable at the time - now we are culling and consolidating to larger volumes.

This command overwrites the device "theDevicePath" (including any and all partitions ) with zeroes:
A good way around but I have to wonder how is this any different than going through the UI in DiskUtility, speed wise?
 
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KALLT

macrumors 603
Sep 23, 2008
5,380
3,415
A good way around but I have to wonder how is this any different than going through the UI in DiskUtility, speed wise?

I do not think that it matters. Disk Utility and diskutil are exposed to the same system frameworks. I doubt that there are quicker solutions. Encrypting the drive now will not be quicker either, given that the encrypted data has to be written too. I have a Raspberry Pi for this kind of long tasks.
 

simonsi

Contributor
Jan 3, 2014
4,851
735
Auckland
Overwriting is overrated - in the 1980's the police in the UK decided physical destruction was the only way after IBM informed them in testing they could read back through 9(!) overwrites...
 

grahamperrin

macrumors 601
Jun 8, 2007
4,942
648
… in the 1980's the police in the UK decided physical destruction was the only way after IBM informed them in testing they could read back through 9(!) overwrites…

As there are light and heavy approaches to physical destruction, so (now) there are light and heavy approaches to soft destruction. .

In the 1980s the soft approach would have been relatively light.

… Raspberry Pi supports large disks?

I don't have one but I assume that the size is relatively unimportant when the computer deals with only small parts of a disk.
 
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