A small ESXi host can be used for the witness appliance.

For booting ESXi use a USB, SD or SATADOM device.

These disk cannot be used for booting ESXi

For a Virtual SAN disk configuration a minimal of 1 SSD and 1 Magnetic disk is needed.

Deploy Virtual SAN on certified hardware.

There is no need to have a physical SSD disksin the ESXi host were the witness appliance resides.

The virtual witness appliance can be configured in the following flavors (depending on the supported VMs):.The VMs are only protected by a single failure (FTT=1).The witness hosts stores only VM witness components (metadata).It is not supported to run the witness on Virtual SAN.The witness appliance is a nested ESXi host (ESXi running in a VM).This hosts does not need a Virtual SAN license and SSD disk.

The witness appliance is placed on a third ESXi server.

With Virtual SAN ROBO, a witness appliance is needed.

Here are some considerations for using Virtual SAN ROBO:

A witness appliance is running on a ESXi server in the same or other site.This can can be 1 ESXi host with Virtual SAN and the witness or 2 ESXi hosts with Virtual SAN.Ī Virtual SAN ROBO environment example looks like this: The witness node can reside in the same or another location (not on the Virtual SAN).Ī virtual witness appliance is needed when a split brain occurs or performing maintenance to figure out what VMs does have quorum (more than 50% VMs objects needs to be available). The Virtual SAN data nodes can be in one location.

In a ROBO configuration you have two Virtual SAN data nodes and one witness node. Virtual SAN requires minimal 3 ESXi hosts. With version 6.1 of Virtual SAN, Remote Office/Branch Office (ROBO) and small SMB customer environments are supported with Virtual SAN on 2 ESXi nodes. With a 2 node Virtual SAN cluster options such as HA, DRS and vMotion are fully supported.

Vmware horizon 8 2106