The user guide says the TS-464-8GB doesn’t have upgradeable memory. Also, note that this model only supports PCIe 3.0. While your Samsung 990-series NVMe will still work, it will only operate at PCIe 3.0 speeds in this model.
Thank you Becker2020 & KarmannGhia! (I had a Latin teacher - a Scot - who drove a Karmann Ghia c. 1966 - an interesting mix of skills.) sigh The 8GB limit is a drag. Onward to greater glory … a RAID 5 implementation. Again, thanks!
The wording is a bit confusing, you mean the system pool (or system volume on QTS), …partition would imply the OS (and there is no way around having md9 and md13 replicated on all disks, besides failing them out manually afterwards)