After rebooting kraken to take a photo, I found nagios was displaying an error for my smartmon checks: NRPE: Unable to read output.
Running the command by hand on the nagios server, I found:
$ /usr/local/libexec/nagios/check_nrpe2 -H kraken -c check_smartmon_ad24 NRPE: Unable to read output
But from the remote server I got:
# /usr/local/libexec/nagios/check_smartmon -d /dev/ad24 OK: device is functional and stable (temperature: 29)
I restarted npre and the problem went away… not sure what this is yet….