failed disk became available after a node reboot

[AlexeyF]

Hi

We had a SATA disk in a failed state for a while (few months) in an old disk aray FAS8040.

One day we've noticed that this disk was no more failed but spare.

I assume that it has happened due to a reboot of a controller node. 

I don't like this behaviour. Can we rely on that disk or is it better to force its recognition as faulty?

Thanks

[RossC · Accepted solution]

Hi @AlexeyF 

I am not sure exactly what is happened here (without diving into the logs) but something to keep in mind is that ONTAP has capability built into it to handle certain scenarios with drives where it might initially detect it as "pre-failed" but then re-use the disk later on as the checks on the disk have completed and determined it's useable. 

Additionally sometimes the behaviour you have reported could be related to a known drive firmware bug, so the disk may actually be fine, but there was a firmware issue that caused the behaviour. Upgrading any disk firmware is advised.

Additionally, updating the DQP (Disk Qualification Package) is another good idea as it can affect how ONTAP detects drive models. 

Hope this helps.