---
title: "VAST Cluster 5.5.2 Release Notes"
slug: "vast-cluster-5-5-2-release-notes"
tags: ["5.5"]
updated: 2026-10-27T23:00:54Z
published: 2026-10-27T23:00:54Z
canonical: "docs.vastdata.com/vast-cluster-5-5-2-release-notes"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vastdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# VAST Cluster 5.5.2 Release Notes

This release is only available for VAST on Cloud clusters.

- [New Features](/docs-5-5/docs/vast-cluster-5-5-2-release-notes#new-features)
- [Enhancements](/docs-5-5/docs/vast-cluster-5-5-2-release-notes#enhancements)

## New Features

#### VoC on Azure

Release 5.5.2 introduces Polaris-based cloud deployments on Microsoft Azure. VoC on Azure clusters support:

- Deployment expansion - to increase usable storage capacity of a running VoC cluster by adding more hosts to it
- VM maintenance - to prevent service disruption during planned maintenance of the VMs
- Hibernation - to preserve data and metadata while dropping a VoC cluster, with the ability to later restore on a new VoC cluster.

#### Hibernation

Starting with release 5.5.2, VoC deployments support cluster hibernation.

Hibernation lets you shut down all of the cluster's VMs while preserving the data and metadata on an object store (such as AWS S3 or Azure Blob), with the ability to resume service as soon as new VMs are deployed.

You initiate hibernation via the VAST Polaris UI or VAST Cloud CLI.

Requirements and limitations are as follows:

- Hibernation is supported for AWS and Azure deployments only.
- The old and the new deployment must have the same number of VMs, instance type, availability zone, and VAST version.
- Hibernation cannot be performed during deployment expansion, VM decommission, upgrade, metadata rewrite or write buffer rebuild.

> Note: Hibernation is allowed when there is a pending maintenance operation.
- Hibernation cannot be performed if an EBS device is missing.

## Enhancements

### VAST on Cloud (VoC)

- Added support and optimizations required for running VoC clusters on AWS EC2 i8g instances (`i8ge.24xlarge`).
- ORION-394347: Added user controls to cancel the process of resuming cluster operation (in addition to controls available in the Polaris UI):
  - In VAST CLI, the `cluster cancel-resume` command
  - In VAST REST API, the `/clusters/<ID>/cancel_resume/` endpoint.

## Limitations

### VAST on Cloud (VoC)

- VAST Cloud (Polaris) UI does not provide an option to run a cluster upgrade. Cluster upgrades are to be performed using the VAST Web UI.
- VAST on Cloud clusters do not support OS upgrade.
- In the event of downtime, data is rebuilt while the cluster comes back online. In case of a subsequent failure during the rebuild, data integrity is not guaranteed.
- ORION-327048: For VoC on GCP, it is recommended to have a multiple of 8 non-VMS VMs per cluster, since GCP has 8 failure domains and imbalance may result in failed stripe allocations.
- ORION-145141: Creating a tenant with EKM encryption is not supported on VoC clusters.
- ORION-113036: After you reregister the same VoC cluster in Uplink, information about the previously registered instance of this cluster is no longer available in Uplink.