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Got a load of old disk drives that we need to completely wipe of all trace of customers data. Any suggestions what might be the best software available to do this? Do I need anything special or can this be done using any of the Linux Live CDs?
Don't use dd with urandom, it's terribly slow. Go for this instead:
# cryptsetup open --type plain -d /dev/urandom /dev/<block-device> to_be_wiped
# cat /dev/zero > /dev/mapper/to_be_wiped
Another method is shred, which is included with most live CDs in my limited experience. The effect is similar to doing 25 passes of dd with /dev/urandom, but I've no idea how it compares for speed.
It uses dd(1) for disk wiping... use it at your own risk.
It does nothing special... just run repeatedly the dd command as specified in this topic.
By the way... dd wiping is slow. It's acceptable for volumes in the order of 4GB, more is a pain!
Another method is shred, which is included with most live CDs in my limited experience. The effect is similar to doing 25 passes of dd with /dev/urandom, but I've no idea how it compares for speed.
If I remember well, the default is 3. Then you can specify the number of passed with -n option.
Last edited by kooru; 06-20-2014 at 08:33 AM.
Reason: edit: resource man shred
Why not just fill the drive with zeros using dd? Much faster than filling it with random data. It won't be possible to restore any data even when filled with zeros, not with any software anyway. And if the drives contains such sensitive data that it could pose a threat to national security you should physically shred them anyway.
For the most part, you have to write every bit once or more to actually destroy to some degree all data. No matter what you use, it takes time. It is best if you can boot up to the fastest mode the drive can handle.
Some apps may not write all bits, they know that damaging one out of 8 or so the data will be lost. They would be faster.
Dban is one of the favored for this task. It generally uses the fastest means to securely wipe a drive.
Norton's ghost used to be pretty fast as it used file by file. It still may be that one could create a scheme that just put new files over old data. Set it to have smaller files use more area to speed it up.
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