I have upgraded an older CORE server to SCALE and now I want to erase the pool since it is no longer needed. I intend to sell the drives, therefore I want to make sure that the disks are clean.
I am not looking for a paranoid level of erasure; not several wipes or similar tomfoolery. What is the easiest way to achieve this? Is it enough to destroy the pool?
If you have SCALE you would go to Storage and click Export/disconnect on the pool you want to remove.
Check the Destroy data on this pool?-box.
I’ll add that someone can, with specialised applications, possibly recreate the data. You would have to at least do a one pass overwrite if you want to reduce the risk of that.
Unless of course the pool was encrypted in which case it’s enough to export/destroy it since you won’t be giving away the key/passphrase when you sell it.
Yes, but I was hoping to hear something along the lines of:
Yes, I would feel safe with this if this were my disks and I want to sell them
or
No, I wouldn’t count on this being enough. My preferred way of erasure is …
There’s always hdparm and secure erase, but I have done this for a few other disks and it’s getting old. The disks get hot if you don’t have datacenter-levels of cooling, and even for 3 or 4 TB, the process takes 8 hours or more. Any attempt to access them (even for smartctl, sensors or similar) freezes the process.
I just want to assess the safety of a zpool destroy in a real-life situation. I remember dimly that a format on vfat filesystems just removed the pointers and replaced the first letter of the filename, I am looking for a little (but only a little) better.
It is what it is.
The export+destroy option does not go through the whole drive. Which means recovery software can potentially restore what was there.
What does “paranoid level” mean to you? If it’s multi-level overwrites only, a single overwrite might be acceptable.
There’s also the hammer solution, but in that case you’d only be selling the drives as parts, or as a doorstop.
Yes, but I don’t think that there is widespread software which works on zfs, especially if the disks were in a pool and you have only one of them. Would it be correct to assume that this is safe enough?
Then I suppose you could fill part of the disk with zeroes, or random garbage, to make recovery more difficult.
If it was a raidz# pool and you’re not selling a sufficient set of disk as a package, recovery will be impossible anyway.
There’s Klennet ZFS Recovery that comes up regularly in the forum.
Only you can decide if it’s “safe enough” because only you know what the data is, what the value of it to someone else is and where and how you’re selling the drives off.
This is a choice you’re going to have to make on your own.
The problem isn’t really “software that works on ZFS.” I’m 99.9% sure that “destroy data on this pool” just erases the partition table. Assuming that’s the case, someone who could recreate it (which wouldn’t be hard, if that person knew the disks had been used in TrueNAS) would likely be able to import the pool and read its contents if desired. What’s the likelihood of that? I’d guess it’s pretty small. What’s the impact? Only you know what data you’re talking about.
Export with destroy data, then use the “wipe” option to do a “fill with zeros” wipe on each disk.
Just one pass.
Zero passes is not enough, your data will be in the clear… unless it was originally encrypted
I think you can run multiple wipes at once, but I’ve never actually tried. I use it before returning disks for RMA personally.
