SMART error?

Got this email (twice at exactly the same time) last night:

This message was generated by the smartd daemon running on:

host name: freenas
DNS domain: local

The following warning/error was logged by the smartd daemon:

Device: /dev/ada1, Self-Test Log error count increased from 0 to 1

Device info:
WDC WD10EFRX-68PJCN0, S/N:WD-WCC4J3542112, WWN:5-0014ee-25f5645f2, FW:01.01A01, 1.00 TB

For details see host's SYSLOG.

You can also use the smartctl utility for further investigation.
No...

SMART error?