[140am]

"daily backups" should not be on the same storage (or one could argue location) as your hot storage which has your photography data. How much of active storage do you have and access on a constant basis?

I personally keep local storage in the TB range (think drobo.com and local disks on workstation) and offload everything else to multiple cloud providers with a backup tool I trust (which I test on a daily basis by restoring data from the backup set of individual machines - example laptop vs home machine). Backup data resists on a mixture of cloud backends ranging from SFTP, Amazon Glazier/S3 and Dropbox. If most of your 12TB+ is backup/cold storage, you should be able to offload it to providers like crashplan.com or amazon drive which offer 'unlimited storage' for a few dollars if you are looking for a low cost solution and are willing to wait a year for your backup to complete.