Assistance Needed: Enabling Fault Tolerance (FT) using vSphere's Virtual SAN (VSAN)

[Anil12]

Hi All,

I'm currently working on configuring Fault Tolerance (FT) for specific virtual machines (VMs) on two ESXi hosts, without the need for additional NAS storage. After some research, I've learned that this can be achieved using vSphere's "Virtual SAN" (VSAN) feature. VSAN allows us to utilize local storage on the ESXi hosts to create a shared datastore, which can then be utilized for FT purposes.

Here are some details regarding our setup:

We have two ESXi hosts: ABC and XYZ.
The ABC ESXi host has 8 VMs, while the XYZ ESXi host has 5.
Our objective is to enable FT for three specific VMs on the ABC host only.
Each host is equipped with the following specifications:
4 x FC 10G ports
128 GB RAM
64 core processor
5 TB of storage space with RAID 1 and RAID 6 configurations.
I have already installed ESXi version 8.0.2 on both hosts, and I am now seeking guidance on the entire configuration process.

Could someone please provide me with detailed instructions or guide me through the configuration steps based on the provided details?

Your assistance in this matter would be greatly appreciated.

Thank you for your support.

[pcgeek2009]

 

In terms of your servers, there are some disk requirements as shown below. Make note of the third item, storage controllers. You mention you already have it configured with RAID 1 and 6. However, VSAN needs direct disk access. In many cases, RAID HBA's are not configured by default for this use. I now with HPE, you have to run a command line in the utility to set if for pass-through. You will also need a third or host (could even be something like a Raspberry PI (not sure I would do that in a production environment) to run a witness node on. 

Storage Component Requirements

Cache	One SAS or SATA solid-state disk (SSD) or PCIe flash device. Before calculating the Failures to tolerate, check the size of the flash caching device in each disk group. For hybrid cluster, it must provide at least 10 percent of the anticipated storage consumed on the capacity devices, not including replicas such as mirrors. vSphere Flash Read Cache must not use any of the flash devices reserved for vSAN cache. The cache flash devices must not be formatted with VMFS or another file system.
Capacity	Hybrid group configuration must have at least one SAS or NL-SAS magnetic disk. All-flash disk group configuration must have at least one SAS, or SATA solid-state disk (SSD), or PCIe flash device.
Storage controllers	One SAS or SATA host bus adapter (HBA), or a RAID controller that is in passthrough mode or RAID 0 mode. To avoid issues, consider these points when the same storage controller is backing both vSAN and non-vSAN disks: Do not mix the controller mode for vSAN and non-vSAN disks to avoid handling the disks inconsistently, which can negatively impact vSAN operation. If the vSAN disks are in RAID mode, the non-vSAN disks must also be in RAID mode. When you use non-vSAN disks for VMFS, use the VMFS datastore only for scratch, logging, and core dumps. Do not run virtual machines from a disk or RAID group that shares its controller with vSAN disks or RAID groups. Do not passthrough non-vSAN disks to virtual machine guests as Raw Device Mappings (RDMs). To learn about controller supported features, such as passthrough and RAID, refer to the vSAN HCL: https://www.vmware.com/resources/compatibility/search.php?deviceCategory=vsan

vSAN Express Storage Architecture storage device requirementsStorage Component Requirements

Cache and capacity

Each storage pool must have at least four NVMe TLC devices.