VMware Cloud on AWS Storage Sizing Quick Reference Guide
This VMware Cloud on AWS storage sizing guide is a quick reference for the usable storage you get per host, across i3i, i3en, and I4i clusters of 2 to 16 hosts. Use it to estimate capacity before you size a cluster, plan a host type change, or check how much usable space a given cluster size actually delivers once vSAN’s data protection overhead is accounted for.
For up to date info always use the official sizing tool located here
VMware Cloud on AWS host types covered here
This guide covers the i3i, i3en, and I4i host types. For host specs and background, see An in-depth look at VMware Cloud on AWS hosts and VMware Cloud on AWS i3en Host: Specs, Storage & Performance. The newer I7i.metal-24xl host isn’t in the official sizing tool yet, so it’s listed in the table below without figures – see New VMware Cloud on AWS Host: i7i.metal-24xl for what’s known so far.
VMware Cloud on AWS storage sizing table (vSAN OSA, 2-16 hosts)
This is based on vSAN OSA and excludes the management overhead (i.e. valid for secondary clusters). It also uses the most efficient storage policy that is supported based on the number of hosts available.
Each row shows the usable capacity per host once vSAN’s storage policy overhead is applied, not raw disk capacity. Multiply by host count for a rough cluster total, then validate against the official sizing tool for your specific configuration.
| Host Type | i3i | i3en | I4i | i7i.metal-24xl | |
|---|---|---|---|---|---|
| No of Hosts | TiB Available | TiB Available | TiB Available | TiB Available | FTT in use |
| 2 | 11.2 | 41.39 | 18.48 | 12.28 | FTT1 RAID1 |
| 3 | 16.8 | 62.09 | 27.71 | 18.41 | FTT1 RAID1 |
| 4 | 33.68 | 124.49 | 55.57 | FTT1 RAID5 | |
| 5 | 42.1 | 155.61 | 69.46 | FTT1 RAID5 | |
| 6 | 44.8 | 165.57 | 73.9 | 49.11 | FTT2 RAID6 |
| 7 | 52.26 | 193.17 | 86.22 | 57.29 | FTT2 RAID6 |
| 8 | 59.73 | 220.77 | 98.54 | 65.47 | FTT2 RAID6 |
| 9 | 67.2 | 248.36 | 110.85 | 73.66 | FTT2 RAID6 |
| 10 | 74.66 | 275.96 | 123.17 | 81.84 | FTT2 RAID6 |
| 11 | 82.13 | 303.55 | 135.49 | 90.03 | FTT2 RAID6 |
| 12 | 89.6 | 331.15 | 147.8 | 98.21 | FTT2 RAID6 |
| 13 | 97.06 | 358.74 | 160.12 | 106.4 | FTT2 RAID6 |
| 14 | 104.53 | 386.34 | 172.44 | 114.58 | FTT2 RAID6 |
| 15 | 112 | 413.94 | 184.75 | 122.77 | FTT2 RAID6 |
| 16 | 119.46 | 441.53 | 197.07 | 130.95 | FTT2 RAID6 |
VMware Cloud on AWS storage sizing table (vSAN ESA, 2-16 hosts)
| I4i | i7i.metal-24xl | FTT in use | |
|---|---|---|---|
| No of Hosts | TiB Available | TiB Available | |
| 2 | 20.98 | 18.41 | FTT: 1, RAID: 1 |
| 3 | 41.96 | 36.83 | FTT: 1, RAID: 5 |
| 4 | 55.94 | 49.1 | FTT: 1, RAID: 5 |
| 5 | 69.93 | 61.38 | FTT: 1, RAID: 5 |
| 6 | 83.91 | 73.66 | FTT: 2, RAID: 6 |
| 7 | 97.90 | 85.93 | FTT: 2, RAID: 6 |
| 8 | 111.88 | 98.21 | FTT: 2, RAID: 6 |
| 9 | 125.87 | 110.48 | FTT: 2, RAID: 6 |
| 10 | 139.86 | 122.76 | FTT: 2, RAID: 6 |
| 11 | 153.84 | 135.04 | FTT: 2, RAID: 6 |
| 12 | 167.83 | 147.31 | FTT: 2, RAID: 6 |
| 13 | 181.81 | 159.59 | FTT: 2, RAID: 6 |
| 14 | 195.8 | 171.86 | FTT: 2, RAID: 6 |
| 15 | 209.78 | 184.14 | FTT: 2, RAID: 6 |
| 16 | 223.77 | 196.42 | FTT: 2, RAID: 6 |
How FTT and RAID policy affect VMware Cloud on AWS storage sizing
vSAN raises its data protection policy as the cluster grows, which is why usable capacity above doesn’t scale in a straight line. At 2-3 hosts, only FTT1 with RAID-1 mirroring is available – it tolerates one failure but costs more capacity. At 4-5 hosts, FTT1 with RAID-5 erasure coding kicks in, improving efficiency. From 6 hosts up, vSAN moves to FTT2 with RAID-6, tolerating two simultaneous failures while keeping reasonable efficiency at scale.
In practice, usable capacity per host is highest right at the top of each policy band. If your workload allows it, sizing for 4 or 5 hosts rather than 3, or 6 or more rather than 5, gets you more usable storage for the same policy.
Cluster conversions and management overhead
If you are planning to do a cluster conversion between host types then the management stack size doesn’t change.
What does change is usable capacity at each cluster size, since host types differ in raw capacity per disk group. Re-check the table above for the new host type before committing to a conversion.
vSAN ESA storage sizing in VMware Cloud on AWS
VMware Cloud on AWS also supports vSAN ESA (Express Storage Architecture), which changes the storage efficiency math compared to the OSA table above. For what changed and why it matters, see vSAN ESA in VMware Cloud on AWS: What Changed in VMC M24. A full vSAN ESA storage sizing table for 2-16 hosts, matching the format above, is coming soon.
