SMART error Offline uncorrectable sectors is this serious?

Question

I install freenas and activated smartd and I got a report of 3 faulty drives.

On drive /dev/ad20 (Western digital green 1500gb)

Device: /dev/ad20, 4 Offline uncorrectable sectors
Device: /dev/ad20, 6 Currently unreadable (pending) sectors

On drive /dev/ad12 (Western digital green 1500gb)

Device: /dev/ad12, 5 Offline uncorrectable sectors
Device: /dev/ad12, 5 Currently unreadable (pending) sectors

On drive /dev/ad14 (Brand new SSD OCZ 30gb)

Device: /dev/ad14, Failed SMART usage Attribute: 9 Power_On_Hours.
Device: /dev/ad14, 161 Offline uncorrectable sectors

I tested /dev/ad12 with DLG Diagnostic and I got no error.

Answer 1

What is really important is any changes. If those values increase then you have problems. If they remain stable then, while not ideal, the situation is probably acceptable - assuming of course you have working backups.