How to tell which USB has been 'degraded'

[fahadshery]

Hi,

My boot pool is showing degraded. summary in the table below. I am running FreeNAS on 2 USB devices. How do I know which one to replace or if it's indeed degraded?

thanks

Pool Name	Status	Read Errors	Write Errors	Cksum Errors	Used %	Scrub Repaired Bytes	Scrub Errors	Last Scrub Age	Last Scrub Time
ZPool Status Report Summary
freenas-boot	DEGRADED	0	0	0	19%	0	0	4	00:01:34

 

[Samuel Tai]

Run zpool status -v freenas-boot. This will yield the gptids of both members of your boot pool mirror. Assuming these are running on da0 and da1 (alter as necessary for your boot pool), run gpart list da0 and likewise with da1 to get the rawuuids matching those gptids. This will localize the degraded drive.

As to which physical drive corresponds to da0 and da1, that's a bit more difficult. If the USB devices answer to SMART (most don't), you could run smartctl -i /dev/da0 and likewise with da1 to get the device serial numbers. Alternatively, you could run dmesg | grep umass to see which physical USB port was occupied by da0 or da1 on boot.