Right now Sizer’s automatic sizing does not take into account Erasure Coding savings when it figures out the recommendation. Fortunately the savings is taken into account in terms of HDD utilization.
So the usable capacity and the utilization is accurate, but the recommended node count could be high depending on the settings for compression among other things
This is easy to check and adjust if needed.
Go to manual sizing and decrement the node count.
Two things to keep in mind
- The minimum number of nodes for Files is 4 as there is a FSVM on three nodes and 4th node is needed for N+1 (one node can be taken offline and still 3 nodes to run the 3 FSVMs). So 4 nodes are needed independent of capacity.
- Second, like any Nutanix cluster you want to make sure you still are at N+1. Here is table that shows you max HDD utilization (Files is a HDD heavy workload) you want to assure N+1. For example, if you have 6 nodes and the HDD utilization is UNDER 75% you can be assured that you are at N+1. Here the N+0 target (utilization after lose a node) is 90%, meaning with a node offline the utilization is 90% or less.
| Node | N+0 Utilization Target | Max Threshold for N+1 |
| 4 | 90% | 67.50% |
| 5 | 90% | 72.00% |
| 6 | 90% | 75.00% |
| 7 | 90% | 77.14% |
| 8 | 90% | 78.75% |
| 9 | 90% | 80.00% |
| 10 | 90% | 81.00% |
| 11 | 90% | 81.82% |
| 12 | 90% | 82.50% |
| 13 | 90% | 83.08% |
| 14 | 90% | 83.57% |
| 15 | 90% | 84.00% |
| 16 | 90% | 84.38% |
| 17 | 90% | 84.71% |
| 18 | 90% | 85.00% |
| 19 | 0.9 | 85.26% |
| 20 | 0.9 | 85.50% |
| 21 | 0.9 | 85.71% |
| 22 | 0.9 | 85.91% |
| 23 | 0.9 | 86.09% |
| 24 | 0.9 | 86.25% |
| 25 | 0.9 | 86.40% |
| 26 | 0.9 | 86.54% |
| 27 | 0.9 | 86.67% |
| 28 | 0.9 | 86.79% |
| 29 | 0.9 | 86.90% |
| 30 | 0.9 | 87.00% |