The 4TB EX2 model is advertised as RAID1 configured and 4TB. I believe what is actually included are 2 2TB drives and the 4TB value is only available if RAID1 is turned off and RAID0 used instead. If RAID1 is used, then total storage is 2TB., Is this correct?
Yes. Or more strictly slightly below 2TB, due to block sizes on the drives themselves (as with any hard drive).
Basically as both drives are running in parallel with each file getting written twice (once to each drive) it makes most sense to just display one of them, hence why it appears as 2TB.
If you use spanning, JBOD or RAID0 the capacity will appear as 4TB, but you’ll of course then lose the data duplication across the drives.
Appreciate the confirmation. Advertising it as 4TB and RAID1 is a bit misleading, as you only get half that (or slightly less than half as you point out).
I don’t disagree at all, but it’s what all RAID1 or higher device vendors do.
And I think if you look closely at the small print on the packaging, it does mention about the RAID1 halving of available capacity (at least the packaging of my MyCloud Mirror did).
Not to mention the fact that most disk drive manufacturers calculate and specify MB and GB etc. in decimal (1MB=1000KB, 1GB=1000MB) where as PCs/Macs use the (arguably) more correct powers of 2 based calculations where 1MB=1024KB and 1GB=1024MB.
So the space reported by your PC/Mac will be less again.