Does SolusVM 2 support High Availability?

Question

Does SolusVM 2 support High Availability for Virtual Servers?

Answer

Yes. High Availability (HA) is generally available starting with SolusVM 2 version 2.0.0-43370.

With HA enabled, Compute Resources that share a common storage are grouped into a "Failover Domain". If a Compute Resource in the domain becomes unavailable, its Virtual Servers are automatically placed on another Compute Resource in the same domain, without manual intervention.

How to enable it

1. Update SolusVM 2 to version 2.0.0-43370 or later.
2. Enable High Availability in the global settings.
3. Create a Failover Domain and add the Compute Resources that share the same storage.
4. Offer HA to your users through your plans.

Step-by-step instructions are available in the documentation: High Availability.

Requirements and limitations

Before enabling HA, please review the requirements. In short:

• A Failover Domain requires at least two Compute Resources. A domain with a single Compute Resource is reported as Not protected.
• All Compute Resources in the domain must use the KVM virtualization type. Virtuozzo Compute Resources are not supported for HA, even when they host KVM Virtual Servers.
• All Compute Resources in the domain must use Shared LVM (iSCSI) or NFS storage.
• The remaining Compute Resources must have enough free CPU and memory to run the Virtual Servers after a failover.
• Use a dedicated shared storage for each Failover Domain. Sharing one storage between several domains is not supported.
• The location and the storage of a Failover Domain cannot be changed after the domain is created.

The full list is available here: Requirements and Limitations.

Note: If you use Shared LVM storage, follow the Adding Shared LVM Storage guide, including the steps to arm the watchdog. On some distributions the watchdog is not armed by default.

Offering High Availability via WHMCS

The official SolusVM WHMCS VPS provisioning module supports HA starting with version 1.0.62. It adds an Enable High Availability configurable option, available both when a customer orders a new product and when an existing one is upgraded.

When the option is selected, the Virtual Server is placed on a Compute Resource protected by High Availability. Because enabling HA migrates the Virtual Server, the customer is asked to confirm the change, and the Virtual Server may be temporarily unavailable during the migration.

To use HA from WHMCS, both SolusVM 2 (2.0.0-43370 or later) and the module (1.0.62 or later) must be updated.

Configuration instructions: Enable High Availability.