Critical alarm message

[Ghost Tsang]

I got the critical alarm message with FreeNAS, please let me know how to fix it

• CRITICAL: Aug. 16, 2017, 8:34 p.m. - Device: /dev/ada6, 2 Currently unreadable (pending) sectors
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• CRITICAL: Aug. 16, 2017, 8:34 p.m. - Device: /dev/ada7, 3 Currently unreadable (pending) sectors
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  CRITICAL: Aug. 16, 2017, 8:34 p.m. - Device: /dev/ada0, 80 Currently unreadable (pending) sectors

FreeNAS-9.10.2-U3 (e1497f269)

 

[Artion]

Take a look at this.