For small environments, VMware’s software defined storage ‘vSAN’ is a very nice for solution for a shared storage between multiple hypervisors, which gives you the ability to use enterprise features like HA and DRS.
But if your environment is too small, you may got a few problems because vSAN needs some requirements:
- at least one SSD drive for caching
- certified hardware (RAID controller, NICs, …)
- dedicated (10G recommended) connection(s) between hypervisors
With NetApp’s software defined storage ‘ONTAP Select’ there is a nice workaround for these requirements. I’ve build a small proof of concept on my demo lab:
Two Dell Hypervisors with 6x 1T SAS drives each, two 10 GbE and two 1 GbE interconnects between both hypervisors. Both hypervisors are using their Dell PERC RAID controller with RAID6, so I’ve got two 4 TB datastore on which one ONTAP select node resides. Both nodes build a HA cluster and provide one big datastore, which is mounted on my VMware hypervisors, too. I migrated all my demo VMs on this shared datastore and now I am able to use HA and DRS with my hypervisors:
ONTAP Select recommends three types of networks:
- NFS backend network for NFS traffic (to my hypervisors)
- Management network
- Cluster backend for cluster and HA traffic
So my demo network looks like this:
ONTAP Deploy is a virtual machine which is used for deployment of the individual storage nodes. If you deploy a 2-Node, you need a quorum to prevent from split brain scenarios – but this is simple, you can just use your ONTAP Deploy for this. But remember to not run ONTAP Deploy on the same hypervisor as your storage nodes. For bigger deyployments, you don’t need a quorum.
ONTAP Select can use an existing VMFS datastore for it’s storage nodes or can access your hypervisor’s hard disks directly for it’s software RAID. I’ve used the existing datastore for my storages nodes, so I can use it for my other VMs as well and don’t need a downtime, if I want to deconfigure this ONTAP Select setup, because I can just migrate my VMs from the Select datastore to my hypervisor’s own datastore.
Depending on your use case, it is possible to deploy a single node cluster or even up to a 8-node cluster.
Please remember: the setup describe above was just a quick proof of concept. For any production use, consult the NetApp Interoperability Matrix Tool.
For further information there is also a very extensive documentaion in the NetApp technical report “ONTAP Select” TR-4517.