You are to be commended for realizing you need backups for your data. However, you do NOT want continuous, automatic backups! Granted, continuous, automatic backups are far more convenient than manually updating backups but they require that your backup drives be connected to the computer at all times. That exposes your backups to the same dangers your internal drives are subjected to, such as malware, drive damage due to voltage spikes and current surges that blow through any surge protection you have (you do have surge protection, right?), theft, natural disaster, user error, etc.
For your data to be reasonably safe, it must exist in at least three separate places with no connection between them (except when updating a backup). Usually, this means on your computer, an onsite backup drive, and an offsite backup drive. Your backup drives must be kept disconnected from power and your computer except while updating the backup.
Backup drives can be regular external drives or internal type bare drives that you put in an enclosure or use a dock to connect them to the computer. I recommend using internal type drives in external enclosures or, especially if you have multiple backup drives, using bare drives for backup drives and inserting them into a dock when updating the backups. I have a hot swap bay (essentially, a dock) built into my computer that I use to plug a bare backup drives into while updating the backup You can get trayless hot swap bays that fit in an unused 5.25" bay.
Onsite backup drives should be kept in a location away from the computer, preferably in another room or, at the very least, out of sight of the computer if in the same room (I'm guilty of the latter). If you have a separate building for your studio, you could keep your offsite backups at home. A safe deposit box at a bank or credit union would be much safer, though less convenient, since your onsite backup drives will be in proximity of your offsite backup drives for far less time).
As long as your data is kept segregated from your OS and programs (usually by keeping it on separate drives, which you apparently do, or on separate partitions), the best way to backup your data is by using a folder/file syncing program, such as the
FreeFileSync (aka FFS). When set to Mirror mode, FFS will compare the drive or folder you are backing up to the backup drive or folder (FFS treats drives the same way as it treats folders), the copy any new or changed files from the drive being backed up to the backup drive, then delete any files on the backup drive that are not on the drive being backed up. This gives you what is essentially an exact copy of the original drive on the backup drive (some System files will be different but that does not affect your data in any way).
FFS also has a Versioning feature, something you stated you want (a wise decision, btw). It works by sending any files deleted from your backup drive to a Versioning folder of drive. For convenience, I use a single folder on a separate drive in my computer for Versioning (it shares space with the folder that I keep my System images in), then I backup that drive to external bare drives. An option would be to use a backup drive that is larger than the data drive so it would have room for the backup in one folder and have a versioning folder for that drive on the same backup drive. Btw, when shopping for drives, avoid 3TB and 5TB HDDs; for some reason, they do not get as good reviews as other sizes.
If a single backup drive can be large enough to hold all the data on the multiple data drives in your computer, you can have a folder on the backup drive for each data drive in your computer. For example, if you have four 1TB data drives in your computer, you could use a 4TB backup drive with four folders on it: one folder for each data drive in your computer. However, I do not recommend that since it would mean all your backups would have to be connected to your computer while updating a single data drive. It would be far safer to have separate backup drives for each data drive in your computer (granted, economic and space limitations may dictate otherwise).
I admit manually doing backups is a royal pain in the...ah...neck (actually, my opinion is about 2 feet lower) but, at least, using a folder/file syncing program is much faster than other backup schemes, such as imaging and cloning, since only new, changed, and deleted files are involved so it's not all that bad. Updating a backup is a simple set it and forget it procedure so all you need to do to update a backup is to connect the backup drive, start up FFS, then let it run until it finishes, then disconnect the backup drive. Assuming your computer is powerful enough, you can still use the computer while the backup updates. Once the update is finished, simply shut down FFS and disconnect the backup drive. Updating your backup as soon as possible after you change or add data will reduce the amount of time for each update, making it a little less inconvenient to do manual backups.
For most people, having one onsite and one offsite backup drive for each data drive in a computer is plenty. However, keep in mind even backup drives are subject to failure (all drives can suddenly fail without warning and hope of recovery no matter their quality or age) and, since your data is critical (you do NOT want to deal with a furious bridezilla because you lost her wedding photos!), you may want to consider having two identical onsite backup drives and two offsite backup drives instead of just one of each. While that option will cost twice as much and will mean you will have to update two backups for each data drive instead of one, that will protect you should one of your data or backup drives dies or gets corrupted during an update (I've had it happen; that second onsite backup saved my
bacon data). Your offsite backups will not have any data that was added or changed since the last time you swapped them out with your onsite backup drives, so this would help ensure your data will not be lost should the unthinkable happen.
If you decide to use two duplicate onsite and offsite drives per data drive in your computer, you could set FFS to automatically update to one of the onsite drives during the day, then disconnect that drive near the end of the day and do a manual update to the second offsite drive (twice a day would be better; you could do the first time during lunch). That way, if the connected backup got corrupted during the day, you would still have the second drive to recover from.
One way to speed up the backup process is to use SSDs for your data and backup drives but that is seriously expensive when dealing with large amounts of data. However, you may be able to justify that added cost as a business expense.
Although FFS is easy to use, especially once the profiles are set up, the instructions for it aren't always easy to understand if someone hasn't used a folder/file syncing program before. However, if you do decide to use FFS, one of us can walk you through setting it up and using it (one of these days, when life stops whomping me upside the head, I need to write a tutorial for it).
