Have a Mac mini and use an external SSD as my boot drive. I use the Internal HDD for a CCC backup. Lately CCC has been falling to complete a Clone and says there are Read Errors on the disk. If I reformat it will make a Clone and then will work for a few days (1 backup every night) and then quite. The number of errors is now at 316 and keeps increasing. Disk Utility/First Aid says all is fine and I have even used Secure Erased to write over the disk and it works fine. Is the disk defective and how do I tell? Does Disk Utility/First Aid not really work well or is it right? Also not sure what the best forum to post in so Mods move if you feel it is wrong.