A Qnap NAS has a drive with some bad sectors, I want to RMA it, but before just want to figure out how to prepare a drive? It’s part of a raid 5 setup of 4 drives unencrypted. So I want to remove it and wipe it. Got a Linux machine I can use, but never done this before.
What are common Linux tools to do that sensibly?
If the drive has bad sectors that it can’t read right now, it likely had other sectors that were marginal and got copied (remapped) to new spare sectors before they became unreadable. So there is still potentially recoverable data in the remapped sectors, and not much you can do about it.
Basically, writing zeros to the disk is about as good as you can hope for. If your data is s00per seekrit to the point where you can’t stand the possibility of any bits at all being recovered, you basically have to melt the drive. Otherwise, zero it and send it in.
Next time, set up encryption ahead of time, so your new drives never see plaintext. Some drives have a “secure erase” feature that is basically a crappy version of this built into the drive.