What happens when you pull 2 Disks from a RAIDZ1 ZFS Pool?

[sgtpepperaut]

Hello fellow Freenasers,

I was contemplating the scenario what actually happens when you pull MORE thank one disk from a RAIDZ1 pool.
Assuming the disks are perfectly fine will the ZPOOL happily mount again?

I understand that the pool will of course not mount when you pull more than 1 disc from a RAIDZ1 but my question simply is about resilience against accidental unplugs of individual drives.

 

[sretalla]

While the given number of disks (for RAIDZ1 it's n-1) are not present, the pool will be unavailable.

If the missing disks are added back, the pool will become healthy again after a (usually quick) resilver to ensure everything is consistent (mostly checking that the contents of the returned disks hasn't changed since last seen).

Generally, with an accident like that, you will only have a few minutes before things get back to normal.

 

[joeschmuck]

Agreed, if the pool never mounted then there is no damage to the pool once you reinstall at least one of the two pulled drives. This actually happens more often than you would think but because there is no pool damage, you rarely hear of it. Most people don't like to say they screwed up. I've done it when moving from one case to another or replacing the motherboard. It happens.