If an EX2 board fails, there are ways to pull data off a Raid 1 (mirrored) drive directly to a PC/Mac. It involves a drive enclosure and a Linux driver for your PC/MAC.
But there are other reasons to have a USB backup. . . that is not on the same premises as the NAS unit.
EDIT: I have not had to do this myself, but I understand that recovering data from a NAS drive is not superhard. Basically, you simply get a $30 drive enclosure, plug the drive into the enclosure and plug the enclosure into a computer. Now, the complication is that most NAS units are Linux boxes. Formatted as EX4, which PC’s and MAC’s can’t read natively. At this point, I believe there are a number of low cost or free programs you can run to allow a MAC or PC to read the drives, and transfer data to a more suitable spot
EDIT: I guess it is worth emphasizing: BACKUPS are key. A NAS is PART of a backup plan. Simply having a Raid One NAS is not a comprehensive solution.
Ransomware corrupts all drives in the NAS. A “mirror” or “stripped” drive system won’t help if all versions are corrupt.
The NAS is sitting next to your computers. . . and you have fire or a lightning strike that wipes them both out
You delete a file on the PC by mistake. You backup the PC to a NAS. . . before you find the error
This is my personal approach:
No data resides on PC’s. A rogue O/S update can’t take out my data. All my “data” lives on external drives. This allows me to by PC’s with smaller hard drives, and allows me to switch between PC’s easily.
External drive is backed up to a NAS regularly. If I lose the HDD drive… . .if the drive breaks. . . .no data is lost.
External drives are replaced every 12-18 months. This allows me to use a drive that is no more than 18 months old. The old drive becomes a “safe point” that sits in a drawer pending an issue that corrupts my main data and my backup
If the NAS breaks, or a random NAS O/S renders the NAS unusable . .well. . .all the data is on the USB drives.
NAS is backed up periodically to an external drive which I put in my desk drawer at work. If my house burns down. . I only lose a couple of months of files. . .not decades (I’m old)
This may all sound paranoid. . … but over the years, I have had bad things happen. THAT IS THE NATURE OF LIFE.
- I have personally experienced a “non-optional” Win10 O/S “update” wipe out a computer.
- I had a house severely compromised by a natural disaster (flood).
- I have had a number of HDD failures over the years (most recently this week)
- I corrupted a moderately important file. . and found the issue five years later. I had to go all the way back to an old 100mb ZIP disk (Remember those? Those were the Bee’s Knees before the days of cell phones)
- I travel a fair bit. . . .been through more than 2 natural disasters while travelling. . . .it’s always good to know that the computer bag is not a “must have” when in is “Time to Flee”. Just make sure I have my passport, a credit card and cell phone. . . and GO