Can any data from a zpool be recovered if a malicious user gains access to 1 HDD?

[shackrock]

Hey all, I had a hard drive fail and I am RMAing it. I'm just wondering, is it possible to recover data from this drive (that was in a 6-disk RAID-Z1 Zpool)? i.e. Do I need to try to wipe the drive for any reason, or is this data completely random without the rest of the Zpool present?

Thanks

 

[cyberjock]

Well, in theory, the data is striped across all of the drives, along with parity. If they were to run a program that tries to sift for particular file types(txt, jpeg, etc), and the file is smaller than the stripe size, they have a chance of finding the data. So technically, I'd say there is a non-zero chance of them recovering data. But do they care enough to look at your exact disk among the 100s(or 1000s) they receive ever day? If the drive is so broken you're RMAing the drive, its possible you won't be able to complete a disk wipe anyway(it'll get stuck at some point and probably not be able to continue).

If you are that worried about it you should use a zpool with encryption. Then they'd not only have to decrypt the drive, they'd also have to sift for data types. I generally just RMA the drive and don't worry about the fact that the drive had personal files on it, but I do delete the partition table(which is pretty much N/A for ZFS).

Keep in mind most people don't have a clue what ZFS is, so if some Best Buy equivalent geek got a hold of your drive somehow he'd be wondering what file system it had. When it wasn't a standard format(NTFS, FAT32, ext, etc) he'd probably give up.

 

[shackrock]

True. Let me ask a follow up then: Is it possible to encrypt a Zpool once it's already created?

Also, got any good "HDD wipe" programs for windows? If it only takes a few hours, I might as well wipe it with zero's once.

 

[cyberjock]

True. Let me ask a follow up then: Is it possible to encrypt a Zpool once it's already created?

Also, got any good "HDD wipe" programs for windows? If it only takes a few hours, I might as well wipe it with zero's once.

To encrypt the zpool it has to be created that way.

I just use dd if=/dev/zero of=/dev/whatever to wipe a drive.

 

[survive]

Hi shackrock,

If you need to wipe a drive & want to be sure it's "all gone" it's tough to beat Darik's Boot And Nuke (DBAN). It's not quick (multiple beginning-to-end writes of random data simply aren't) and it's not for windows but you can get an .iso of it here:

http://www.dban.org/

-Will

 

[HolyK]

For Windows you can use HD Tune. Zero-write, Random-write, DoD5220 or Gutmann re-write patterns are available. I am using random and zero fill. You don't need to use DoD or Gutmann unless you have some top-secret national / terroristic or some crazy illegal information on the drive. There is no chance to get anything from the drive after zero/random write unless you have magnetic microscope to perform "Second harmonic magneto resistive imaging" :D