Best Practices for SUSE® Rancher Manager Managed VMware vSphere Clusters
This guide outlines a reference architecture for provisioning downstream Rancher clusters in a vSphere environment, in addition to standard vSphere best practices as documented by VMware.
1. VM Considerations
Leverage VM Templates to Construct the Environment
To facilitate consistency across the deployed Virtual Machines across the environment, consider the use of "Golden Images" in the form of VM templates. Packer can be used to accomplish this, adding greater customisation options.
Leverage DRS Anti-Affinity Rules (Where Possible) to Separate Downstream Cluster Nodes Across ESXi Hosts
Doing so will ensure node VM’s are spread across multiple ESXi hosts - preventing a single point of failure at the host level.
Leverage DRS Anti-Affinity Rules (Where Possible) to Separate Downstream Cluster Nodes Across Datastores
Doing so will ensure node VM’s are spread across multiple datastores - preventing a single point of failure at the datastore level.
Configure VM’s as Appropriate for Kubernetes
It’s important to follow K8s and etcd best practices when deploying your nodes, including disabling swap, double-checking you have full network connectivity between all machines in the cluster, using unique hostnames, MAC addresses, and product_uuids for every node.
2. Network Considerations
Leverage Low Latency, High Bandwidth Connectivity Between ETCD Nodes
Deploy etcd members within a single data center where possible to avoid latency overheads and reduce the likelihood of network partitioning. For most setups, 1Gb connections will suffice. For large clusters, 10Gb connections can reduce the time taken to restore from backup.