This sounds familiar from when I migrated to modern hi-capacity drives, although the scale is just massive
First of all, it's okay to migrate: there is no risk
. No more than there is in accessing or regularly backing up that data anyway - mechanically, it is the same as reading those files. In fact, accessing the data for use will probably involve writing (last accessed info, other metadata updates, index file change), and thus is riskier than raw copying. You will have to migrate some day when the drives fail, or capacity is reached - or the backwards compatibility disappears or becomes financially unsustainable.
The investment could be big if there's a lot of data, but it buys you performance, security and actual peace of mind. Can't put a price on the last one.
For raw copying when migrating, you could use FBackup's (link)
(freeware, no nags, no bs) direct copy and verify function. This way you can be sure you got 1:1 copies
. Much better than Ghost for backups too, since you make actual file copies and not archives in a proprietary format
that may or may not be a disaster come recovery time (AND you can access the copies from any secondary client!
). I lost 4/6 of my backup archives using Ghost 14, and to add insult to injury, it didn't even work with the new OS (Windows 7 64-bit) that I had bought to run on the new machine I wanted to transfer to. Ghost might still be good for making an image of the OS drive if you're moving to a new PC altogether.
In the end, I went from owning 6 noisy, hot HDDs and a USB backup drive to owning just two HDDs and a NAS. I have all my data, less points of failure in the system and a working, fast and intelligent backup AND file server system (remote access is so nice). USB sucked hard both for security (usually no SMART, poor cooling, external power) and speed (it's USB).
If you want to run the drives into the ground and spend money on obsolete interfaces, who's to argue. Some might even say it's a favour to the environment. Moving everything to a single, actively cooled enclosure does sound like a good idea, since 14 drives in individual enclosures sounds like both an orchestra and a fire hazard.