I am looking for help choosing a back system, both the structure of the system as well as the specifics of each component (e.g. recommended drives and/or backup software).
I have about 2TB of photos in my Lightroom library attached to my mid-2011 iMac 27" (with Thunderbolt and Firewire 800 but only USB 2, not USB 3). I want three copies to cycle through the backups - one will be off-site, the other will be my on-site backup, and the third will be the actual drive on which I use my images. These will all be external drives. I have a Belkin Thunderbolt Dock which gives me USB 3 ports. I have a Time Machine drive that backs up my internal hard drive (which does not contain any images but does contain my LR catalog files).
I have been using Carbon Copy Cloner and I am happy with it.
All of my Lightroom images are stored on two 4TB Seagate Expansion Desktop drives set up in a RAID1 (mirrored) which was set up using Apple's Disk Utility (OS X 10.8.5). They are a few months old and one has already failed! I am now very nervous!
My main goals are a robust, reliable backup system. Speed of backup is lower priority in relation to security and peace of mind.
I think I want 4TB drives so that they about half full.
Based on Lloyd Chamber's suggestions (http://macperformanceguide.com/Mac-CostEffectiveBackup.html
), I am considering using this bare drive dock: http://eshop.macsales.com/shop/NewerTech/Voyager/Hard_Drive_Dock/
I would appreciate any recommendations or feedback.