Nuke an old RAID set from orbit, it's the only way to be sure...But how?

[praecorloth]

So, I have run in to this particular problem several times over the course of various different releases of FreeNAS going back to a few of the .7 versions.

Drives that are used in a RAID in FreeNAS cannot be re-used in different RAIDs if the first RAID was not properly destroyed. At this point you might think, "Duh." But the kicker here is that this includes scenarios where you move the drives to completely different installs of FreeNAS. This includes if you format the drives in some other OS. FreeNAS is still somehow able to see that these drives were part of a software RAID, hell FreeNAS can even get the name of the RAID that they were a part of. But that's the extent of it. You can't import the RAID. You can't create a new RAID based off of those drives. Those drives are essentially useless in a FreeNAS box now.

The first time I came across this problem was in one of the .7 versions. I was able to get in to the command line and destroy the RAID manually with the geom command. With that command I was able to see the old RAID set up, destroy it and life was good. Things seemed to have changed with 8. Geom doesn't seem to work the same way, or it's not telling me that it still sees the old RAID. I know it still sees the old RAID because when I shut down FreeNAS it says that it is shutting down the old RAID, despite the fact that this is an install of FreeNAS that has yet to have a RAID configured on it.

In short, I need a reliable way to destroy RAIDs that cannot be imported.

 

[tropic]

That was pretty frustrating for me, too, back when I started playing with FreeNAS and was far away from a final config. If memory serves, simply laying down a partition table with a gparted live cd will fix the problem.