Hello Luke,
"2 SSD Write intensive 800GB for cache, and 3 SSD read intensive (or mixed workload) 3,84TB per capacity"
Do you mean 2 Disk-Groups with 1x 800GB cache-tier and 3x ~4TB capacity-tier devices per Disk-Group? Otherwise (e.g. if you mean 3x capacity-tier devices total) indicating non-homogenous Disk-Groups (2x capacity in first Disk-Group, 1x capacity in second Disk-Group) is not optimal.
"- Network if it's better 4 ports 10Gb or 2 25Gb"
You are very unlikely to saturate 10Gb links in a 4-node cluster with this configuration and thus this is unlikely to be a bottleneck - 4x 10Gb links are likely the preferable option here as it will allow better physical segregation (and redundancy) of the vSAN and other network traffic (e.g. Management, vMotion, VM network, FT (if using), backup traffic and iSCSI/SAN networking).
"- Disk, install esxi on Boss controller card 2 SD in raid1"
Something 'inside-the-box' such as BOSS M.2 or SD-cards in R1 is the preferable option in my opinion as a) this leaves more slots for potential future expansion, b) Can do R1 on the devices which you can't do with devices attached to the controller used for vSAN devices and c) if using any controller that has specifics certification/caveats about what can be attached.
"and capacity workload with 3 or 4 disk"
If you mean 3x ~4TB devices per Disk-Group fronted by 800GB cache-tier, this should be more than adeqaute for most workloads - having multiple Disk-Groups really helps with performance.
https://blogs.vmware.com/virtualblocks/2017/01/18/designing-vsan-disk-groups-cache-ratio-revisited/
"- install all management component (vcenter psc horizon ..) on external environment"
If this is possible, I would generally advise this as without vCenter etc. troubleshooting issues (e.g. network connectivity/partition issues) can be difficult for normal-users to troubleshoot. Then again I am pretty biased in my opinion with regard to this as I look at clusters from a support perspective and know too well what troubleshooting huge clusters with no vCenter is like (less of an issue in a 4-node cluster and if you know what you are doing).
Bob
