I had this email from a friend at G-Tech, This was following the question of "Do I upgrade my 1TB G-Safe or do I go for something else" Interesting thought train. Some price changes coming which may alter your perspective a little! Budgets are always a tricky issue so I'll assume less £ is better!
So your library is 1.2TB and growing at around 25GB per week*. Will you keep everything in the library indefinitely or is there a timeline beyond which the images are no longer required? Can you envisage a library size which will never be exceeded? (I think I know the answer).
Upgrading the disk on your older G-SAFE is a good idea and one that many follow. 2TB is currently the largest HDD (3TB will come next but is still a way off). Assume 2 x 2TB drive modules is £340 today. You will need a 3rd drive module to archive 4TB (whilst leaving 1 drive as a slave to mirror your archived drive back to) so cost could be £510? You could probably buy bare 2TB drives more cheaply in the open market but reliability and warranty may be compromised.
Stand-alone, a 2TB G-SAFE is only going to back-up half of your G-RAID. Your G-RAID will be half full in 7 months so G-SAFE strategy will only buy you a relatively short term solution before needing to add more 2TB modules. I'd also be slightly concerned about bare HDD stored in a cupboard for long periods. HDD need to be run up occasionally and at the same time, physical handling should be kept to a minimum. How about a different approach - Another G-RAID 4TB is about £440 (and will fall next week). Mirror your two G-RAID's and you are good for 2 years. During that time, you can develop your back-up / archive strategy further. Have you considered tape for archive solutions? Relatively low cost cartridges and long shelf life (maybe 30 years?) they make sense although good mechanisms (LTO for example) are expensive.
*assumed working photographers data usage
So, there you have it... More questions to consider and decide upon.
Watch this space!