What to do if pool loses too many drives?

[Touche]

In preparation for my random drive faulting issue presented in
https://forums.freenas.org/index.ph...ed-failed-to-read-smart-attribute-data.62657/
what would happen if two drives from the same mirror would become FAULTED? Or a RAIDZ2 would lose 3 disks due to some fluke, but the data and the disks were actually fine and still contain the data.

Would it result in the permanent loss of the pool or would I be able to recover it since the data is intact on the disks? Currently a simple reboot or two solve the problem of one disk FAULTING.

 

[Arwen]

If the data is there and the drive simply went OFFLINE, then yes, you could online the drive and restore ZFS pool health. I personally would run a scrub after such an occurence. EXCEPT if the drive slot, or drive is flaky. In which case, the scrub's disk activity may cause the drive to go offline again.

Basically this is one reason we recommend server grade hardware. Even cheaper tower servers with NAS or enterprise class drives tend to be pretty reliable. That said, anyone could get a SATA or SAS drive, cable or backplane with a manufacturing defect.

 

[Alecmascot]

You lose the pool and you have to recreate it and restore from a backup.

 

[Ericloewe]

ZFS can easily survive scenarios where too many disks are accidentally disconnected, but otherwise fine. Just plug them back in and your data will be there. If some disks were unplugged before the pool went offline, they will be resilvered to bring them back up to speed, which should be very little work.