Let me say to start that in no way do I blame any particular software or hardware failure; or for that matter my own failure. My setup was as follows :- nMP with C1 referenced to Library on Caldigit T3 via TB, backed up using CCC to 2TB WD Green via eSATA.. My whole system then backed up to 4TB (2x4TB raid) Time Machine via eSATA. The Time machine is stored in the next room and the library backup in a cupboard 6m from my desk. I think that most people would accept this as a reasonable backup solution but I accept that it could have been better if cost was not an issue. OK, this is what has happened. Something in the T3 started to go wrong about two months ago (deduced from dates of images affected etc.). Images on the T3 began to open like this in Preview You can see the line, obviously. On seeing this the first time (not this image) as it was not part of my C1 library I assumed that it was a one off - no other image in that file being affected AND no bad images appearing in C1 itself. Not all my stuff is in C1.. Some time passed and as my usage was quite low throughout that time it was a while before I noticed another corrupted image. The alarm bells+panic occurred yesterday when I had cause to view a file of images not looked at for a very long time. To my horror more than 50% of the images were corrupted some to the degree whereby well over 75% of the image was gone! I apologise for not showing them but I am taking a timeout to write this in the middle of trying to retrieve all I can - bit stressed and opening files just to look just seems to be making it worse. You would think that the TM and CCC backups would be the solution. More gloom. At about the time of the degeneration (cause or not I don't know) I changed HDDs to the WD Green and the TM drives to similar. During this process I checked images as the process proceeded to ensure all was well. Those images I checked were fine and the file sizes remained constant. That all meant that the CCC & TM backups both started from scratch at about the time the images began to be corrupted. Each subsequent backup merely transferred the failure unchecked over the next two months. I now have a T3, corrupted. A CCC clone corrupted. A TM corrupted. I cannot lay out money on this, the T3 is out of warranty and I have discovered an inherent weakness in the referenced filling method. The thumbnails do not change when the originals are slowly going "phutt"!!!! Unless the thumbnails (previews) are regenerated C1 (any referenced system I assume) will not show the problem until a bad image is opened...... Any way to end..... Approximate % of images lost 20-25 from a collection in total of 1.5 TB...... I must admit that I would not have set up this way if I was still working and am grateful that the number of personally affecting images damaged is low. But. Coincidence, operating slackness and just plain bad luck can be a killing group to come up against. Really p****d off and kn*****ed. Will leave this mess 'till tomorrow.