High Availability Cluster with Two Nodes – Feasibility and Prerequisites

[Vignesh Ravi]

Hi team,

I would like to confirm whether a High Availability (HA) cluster can function effectively with only two nodes. If this configuration is supported, could you please share the necessary prerequisites and best practices for implementation?

 

[sterzy]

I would like to confirm whether a High Availability (HA) cluster can function effectively with only two nodes. If this configuration is supported, could you please share the necessary prerequisites and best practices for implementation?

Sorry just realized this is about PMG, yes a two node cluster is supported with PMG. HA should work fine, but you might need to carry out a manual recovery to get full functionality back in case of a full disk failure on a node. See the documentation [2].

[2]: https://pmg.proxmox.com/pmg-docs/pmg-admin-guide.html#_disaster_recovery

Only if you use a QDEVICE, see the documentation [1].

[1]: https://pve.proxmox.com/pve-docs/pve-admin-guide.html#_corosync_external_vote_support

 

[Johannes S]

I would like to confirm whether a High Availability (HA) cluster can function effectively with only two nodes. If this configuration is supported, could you please share the necessary prerequisites and best practices for implementation?

Are you talking about a cluster for virtualization or for the Mail gateway?

 

[sterzy]

Thanks, Johannes, for the pointer, I updated my original answer to be relevant to PMG, the short answer is that yes PMG HA should also work with only two nodes. The clustering algorithm in PMG is fairly different from PVE.

 

[Johannes S]

Thanks, Johannes, for the pointer, I updated my original answer to be relevant to PMG, the short answer is that yes PMG HA should also work with only two nodes. The clustering algorithm in PMG is fairly different from PVE.

It's understandable since a lot of people are asking their questions in the wrong subforum and the OP didn't named a product.