I created this thread to warn people who use the hard disk for archiving their photos. Do not leave hard disk dormant for a long time. There is a tendency for the hard disk to lose its track when not used for 2 years. That's the dormancy period - 2 years of non use. So if you have a hard disk that is full and unattended, check on it every 3 months. Just connect it to the computer and see if the contents are still accessible. FYI.