Freenas critical alert - what device is it mentioning?

I have an alert from my freenas box but I do not what what device it is mentioning.

Capture

CRITICAL: May 24, 2018, 3:01 a.m. - The volume vol1 state is ONLINE: One or more devices has experienced an unrecoverable error. An attempt was made to correct the error. Applications are unaffected.

Check under storage -> Volumes? A volume should have the name of vol1. Could be your boot volume but mines called freenas-boot so I assume everyone’s is also (you can check that in System -> Boot -> Status).

A new alert: CRITICAL: May 26, 2018, 5:36 p.m. - The volume vol1 state is ONLINE: One or more devices are faulted in response to persistent errors. Sufficient replicas exist for the pool to continue functioning in a degraded state.

Could it be one of the usb 3 drives i use as cache?errorboot

After doing some forum searching I found a command called zpool status. It is just a usb flash drive for cache. It prob hit its max i/o cycles. I’ll just remove it.

How do I remove the bad storage device from the pool?
need%20to%20remove