[smartmontools-support] Avoid email every day for non-changing state

[Petter Reinholdtsen]

I use the Debian edition of smartmontool on several machines, and two of
these send an email like this every night, while one of them also send a
message with "Device: /dev/sda [SAT], 16 Offline uncorrectable sectors"
every night.  The end result is that I get repeated messages about what
seem to me like an ignorable "issue", which is not getting worse.

-------------------- Start of forwarded message --------------------
To: pere at hungry.com
Subject: SMART error (CurrentPendingSector) detected on host: laptop
Date: Wed, 13 Sep 2023 05:03:13 +0200
From: root <root at laptop.local>

This message was generated by the smartd daemon running on:

   host name:  laptop
   DNS domain: [Empty]

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

Device: /dev/sda [SAT], 16 Currently unreadable (pending) sectors

Device info:
ST500LT012-9WS142, S/N:S0V487C2, WWN:5-000c50-060d4a051, FW:0001SDM1, 500 GB

For details see host's SYSLOG.

You can also use the smartctl utility for further investigation.
The original message about this issue was sent at Sat Oct 30 10:48:33 2021 CEST
Another message will be sent in 24 hours if the problem persists.
-------------------- End of forwarded message --------------------

Would it be possible to change smartd to only report _new_ or changed
issues, for example only when the number of unreadable sectors change?
As it is now, the emails are just noise and I am considering
uninstalling the monitor on the machines in question.

-- 
Happy hacking
Petter Reinholdtsen