This is the usable capacity for each site-scoped pool. ?
In multi-site Stretch Clusters, separate storage pools are created for each site. One pool cannot span sites.
The figures provided here are for each site. We recommend using Storage Replica to synchronously replicate one site to the other. In this scenario, you achieve site fault tolerance for Disaster Recovery, but the second site does not ultimately contribute additional usable capacity.
Storage Efficiency: ?
Mirroring has efficiency. Using only Mirroring gives available capacity.
At this scale, Parity Encoding has efficiency. Using only Parity Encoding gives available capacity.
Combining these in the proportions you've chosen gives overall.
This deployment has total physical capacity, excluding cache.
We recommend setting aside for in-place recovery. This enables Spaces Direct to restore resiliency immediately after drives fail, even before they are replaced. This value is based on your chosen fault tolerance of and your largest drives, which are .
At certain scales, we may recommend more because repairs are constrained to happen on the local node. This can be non-obvious, but trust us -- it's true. The value above includes this consideration. This recommended reserve is not enforced; if you don't have enough, repairs simply have to wait for the replacement drive to complete.
This leaves total physical capacity after reserve.