Storage-only nodes

A storage-only node, also known as storage node, is a VMware Engine node type that does not have any customer-usable cores and only has customer-usable storage. These nodes can be added to a cluster of VMware Engine hyper converged nodes to increase the storage capacity of the cluster without adding cores to the cluster.

Storage-only nodes can only be added to a management cluster with a minimum of three HCI nodes and a workload cluster that has at least two HCI nodes.

Storage-only nodes are available using the Google Cloud console, Google Cloud CLI and VMware Engine API. The storage nodes don't contribute cores or memory to the private cloud and cluster and can't run VMs. You can use the Google Cloud CLI and VMware Engine API to query the number of storage-only nodes in a cluster.

By accessing the vCenter UI, you can identify which ESXi hosts are configured as storage-only nodes by looking at tags assigned to ESXi hosts. You can query for the tag storage_only_node in vCenter and find all ESXi hosts that have this tag.

Limitations

  • When using a cluster made up of two HCI and one storage node, if there's an HCI node failure, there might be only one available HCI node in the cluster to run VMs. This scenario can remain until the cluster adds a replacement node, at which time your cluster is restored back to resilience.

  • You won't be able to use vMotion on a VM to a storage node within a cluster. If you try to perform this action, you may see a vCenter error stating that there are insufficient resources on the storage node. Instead, you can use the vCenter interface to query the "storage-only" tag to find all ESXi hosts that are configured as storage nodes.

  • Converting a storage node to an HCI node and the other way around is not supported.

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