I have a shared drive that I use to backup 3 computers using a backup application, I also have two attached sync drives that I manually sync my images to, and I use BackBlaze as my offsite backup.
Here are my thoughts on backup practices. Sorry, I feel like this is one of those times when you asked me what time it was, and I am telling you how to build a watch.
I like to keep my working drives connected internally on my computer. I think there are speed advantages to keeping files stored that way. I also tend to move files to slower drives when they may not need to be accessed regularly.
It is important to know what the purpose for your backup practice is, disaster recovery, redundancy, versioning, or recovering deleted files. They all may require a little different approach. If you have multiple copies of corrupt files or the incorrect version of a file it does not help the recovery.
Pay attention to backup software and how it chooses what to backup and how long it retains files that you have deleted either intentionally or unintentionally. Some software apps choose by file type and you may need to manually choose some folders to be certain they are backed up. The retention time can be a specific length of time or unlimited.
You need to pay attention to backup schedules as well. Continuous backup is great but if I put 1000 files onto my PC and my backup app and BackBlaze both started running and I am trying to process images at the same time, computer resources can be stretched.
Backups can become bloated over time with unnecessary files. I have several “Do Not Backup” folders that I have identified as folders that my apps should not backup. I use these folders to store files that I know I am not going to need again or can recover from online resources when necessary. Things like manuals, practice files, test files, downloads, and things like that can add up over time if they all get backed up.
I have found cases where a folder was backed up, then I realize I misspelled the folder name, I rename it, and some backup software will back it up again. Not really a problem it just starts to eat up backup space if you decide to restructure your storage system.
I have never had much success recovering system files from a backup if I have a boot drive failure. I have a 500Gb boot drive and my data and images are stored on a separate drive. I do backup certain directories on my boot drive, but I also clone my boot drive every few months. My boot drive is a high speed NVMe and I clone it onto a SSD that costs about $60. If my boot drive fails, I can install the SSD, maybe update a few apps, restore a few folders, and still have access to my data folder on a separate disk. Since my boot drive is only 500Gb it does not take long to clone it. Some cloning apps will allow you to create a disk image to keep as well.
BackBlaze works well and has limitations and advantages. My internet upload speed is only 10Mb so it did take a while to do the initial upload. I currently have about 3.5Tb on BackBlaze so at my current upload speed it would take a couple of months to upload all that data again. If you are fortunate to have 1Gb upload speeds it would take about 8 hours. On a day to day basis now it generally uploads all my new files overnight. BackBlaze by default only retains deleted files for 30 days, you can pay an additional fee to have them retained for a year and pay even more to have them retained indefinitely. You can access your BackBlaze files using a web browser if necessary.
I am not sure about fire safe use for storing drives. Years ago, you could purchase media safes. These safes were designed to protect tape media for longer times in a fire. I do not even know if they are available anymore. Where I live we have tornados as well and I don’t think a fire safe would offer much protection in the event of a tornado.
In all the business environments I have worked with I have installed Raid arrays and they are probably the best solution for preventing interruption from drive failure. If a drive fails the data is still accessible, just swap out the bad drive and let it rebuild. If I had to be certain that I could access my images without having to restore I would install a Raid. There is some storage and processing overhead with using Raid devices.
NAS storage is great as well, NAS with Raid drives is even better. I have never used a NAS Raid device so I cannot speak on the speed or cost advantages. The closest think I have had to a true NAS devices was a shared drive on a Netgear router. It worked well but seemed to become disconnected fairly often. I moved the drive to a shared drive on my main PC and still use the same software and it works much more reliably.
I use OneDrive or iCloud drive for all my day to day documents. I do not store any images that way, but it is a convenient way to store and access working documents from multiple machines. I believe that OneDrive keeps 25 versions of stored documents. OneDrive or iCloud drive also is a pretty easy way to share a few images if needed.
I do like to use an app on my PC called FreeFileSync, then also have RealTimeSync. File sync compares the contents of two directories and allows you to update one directory with another, mirror them, or update one with the other. I do have all my photo directories synced with external drives. I have to run this app manually, but it gives me a way to be certain that the contents of two drives are the same. I use it from time to time to compare the contents of my working image folders with the contents of my image backup directory. This is how I have found that certain directories or file types were not being backed up or that unnecessary files were in on my backup drive.
I like to have a have one copy of my archive/backup drive connected to my computer and one copy stored away. I always know if my connected drive is accessible but I am never sure how that drive stored away is going to work. I have had a case or two over the years when a backup drive worked when I put it in storage but was not working when I connected it the next time.
I like to swap out my drives every few years. The cost of storage seems to be constantly increasing in size and decreasing in cost. My current working image drive is a 5Tb drive so in the next few months I will swap it out for an 8Tb drive. It is my belief that your working drives are under more stress day to day than your backup drives so keeping them current helps reliability.
Marty