The strange thing is that entire system consumes less than 8GB with two identical devices already being mounted. So why would adding a new device require so much RAM?
My guess: the check always calculates with deduplication, even if it's not enabled. To confirm, I tried to add a 4TB device and the requirements jumped to 19GB of RAM, so my guess seems to be correct.
The problem is that after this check, the wizard won't let me assign any caches for the new device. It doesn't trust my judgment at all
Then I went into logs (server events) and saw that there are warnings about running out of storage space on my storage volume, affecting both existing devices. Current available space on the volume in question is 1,77TB. Allocated storage for both existing devices is 1,02TB. This would mean that both existing devices filled up would exceed the available space, but I'm not really expecting my storage to deplete any time soon. Additional disks would be added to the array "long" before actual space would run out.
Also, these warnings are reported only when the server is starting up, which is presumably not very often. So, what's the significance of these warnings and how does StarWind decide that I'm running out of free space?