Product : Microsoft, S2D [SDS]/2019, Datacenter
Feature : Protection Capacity Overhead, Reads/Writes, Data Availability
Content Owner:  Herman Rutten
Mirroring (2N) (primary): 100%
Mirroring (3N) (primary): 200%
EC (N+2) (secondary): 50%-80%
Nested Resiliency (4N) (primary): 300%
Nested Resiliency (RAID5+1) (primary): 150%
Erasure Coding: Microsoft discourages using single parity because it can only safely tolerate one hardware failure at a time. If one server is being rebooted when suddenly another drive or server fails, there will be downtime. If there are only 3 S2D servers, Micosoft recommends using three-way mirroring.

The EC configuration depends on the storage setup (hybrid vs. all-flash) as well as the number of nodes in the S2D cluster.

EC in Hybrid configurations (SSD+HDD):
4-6 Nodes use RS 2+2
7-11 Nodes use RS 4+2
12-16 Nodes use LRC 8+2,1

EC in All-Flash configurations (All SSD):
4-6 Nodes use RS 2+2
7-9 Nodes use RS 4+2
9-15 Nodes use RS 6+2
16 Nodes uses LRC 12+2,1

EC = Erasure Coding
RS = Reed-Solomon
LRC = Local Reconstruction Codes