Why are my NAS's disks spinning up after ~2 1/2 hrs sleep?

As far as I recon, SMART checking will not wake up spun down disks.

The /frontview/bin/check_smart_errors cronjob is scheduled 4 AM every morning.
However, it will detect spun down disks and abort itself if waiting for spinup takes more than 24 hours (and the next scheduling takes place).

Fragments from "/frontview/bin/check_smart_errors"

if [ -f /ramfs/spindown ]; then

  # Check for spindown mode (up to 24 times a day) before continuiing.
  # Avoid waking up spun-down disks.

  while [ $hour -lt 24 ]; do
    if grep -q ":1" /ramfs/spindown; then
      delay_smart=1
      sleep 3600    # Wait an hour before trying again
    else
      unset delay_smart
      break
    fi
    hour=$(($hour + 1))
  done

  [ -n "$delay_smart" ] && exit -1
fi

The second from last row will call exit if all 24 loops were carried out with disks still spun down.

This is from my syslog:
Sep 27 23:47:44 MyNAS noflushd[1743]: Spinning down disks.
Sep 29 19:36:31 MyNAS noflushd[1743]: Disks spinning up after 2628 minutes.

The disks never spun up on the 28th or the morning of 29th - two 04 AM passed without any activity.

However, even after removal of ReadyNAS Remote my disks seem to spin up with no good reason from time to time.

My hunting has to continue I believe... :-)

/f