As per the title, if I do a preclear on the drive, is that enough to wipe it ?

4 hours ago, vw-kombi said:

As per the title, if I do a preclear on the drive, is that enough to wipe it ?

The complete answer to this question will depend on "describe your threat model". If your considered threat involves nation states or people with access to substantial resources for reconstructing your data, you may want to consult military standards for erasing data, most of which call for multiple overwrites with different patterns. This can be a good starting point.

 

For the rest of us, overwriting with zeroes (as in preclear) should be fine - provided it completes successfully (you do note hardware issues on the drives).

 

Note that if your drives are encrypted (using a reasonable passphrase / key) - you don't actually need to do anything, your drives can be considered wiped, for all practical purposes, to anyone who does not have access to your key.

Cheers for the info - not encrypted, not overly worried, its all backups of photo's, vm backups, backups of invoices etc for the business, hence the desire to do something at least - a preclear I will have a go at.

Preclear (single pass) just fills the drives with zeros, which is good enough for a majority of users. A really determined data thief will need highly specialised software / hardware to recover any data from that but in the right hands + some luck, it's actually possible to recover a large amount of data.

 

The more secured technique is to encrypt the entire disk using a secure algorithm and then "throw away the key". I prefer that method because it's more secured than simple preclear while taking the same amount of time to do.

Thanks.  For the future, can you point me to somewhere I can lean about the securing the disk (on an unraid server).  I have started the pre-clear already to save time - as they take a bit.