@peter27284, you could use a tool such as CrystalDiskInfo or smartctl (Linux) to view the drives’ SMART reports. Check the raw values of the Power On Hours and Load/Unload Cycle Count attributes. That should tell you if the drives are autoparking excessively.
Alternatively, the DiskStation has a “S.M.A.R.T. Test” under the “HDD Management” tab. Perhaps it reports the raw SMART values.
Synology DiskStation User’s Guide:
http://www.use-ip.co.uk/datasheets/synologyds1513+userguide.pdf
Otherwise, the following wiki explains how to install smartmontools on your NAS.
How to give your disks and files a health check and repair basic faults:
http://forum.synology.com/wiki/index.php/How_to_give_your_disks_and_files_a_health_check_and_repair_basic_faults
