To cluster 2 pve Servers at my Hoster or not ?

adoII

Renowned Member
Jan 28, 2010
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A customer has 2 Servers at Hetzner in 2 Different IP subnets and in 2 Different Datacenters and asked me to modernize them.
I would install a proxmox pve distribution on each server.

Does someone have experiences if it is a good idea to cluster the servers in a pve cluster ? I could easily create a vlan and a private address range so that the servers will be in the same logical network. But I expect at least some network latencies / outages over time.

The benefit of the cluster is not that big. It is a little easier to manage but since there is no shared storage anyway and we do not extend to migrate vms it does not make a big difference.

Also it should be no problem to cluster the servers via private ip addresses and manage them using the webinterface on public ip addresses, right ?

If I cluster the 2 machines and then find out that it was not a good idea to do so, ist there an easy way to "decluster" the servers again ?
 
Does someone have experiences if it is a good idea to cluster the servers in a pve cluster ?
Depends on which Hetzner Datacenter, i.e., the distance or better said latency between those two nodes.
If it's below ~ 10ms you could think about it, else the cluster may not be stable...

The benefit of the cluster is not that big. It is a little easier to manage but since there is no shared storage anyway and we do not extend to migrate vms it does not make a big difference.
IMO it makes it quite easier to manage than with two, but only if it's stable. For two nodes in different DCs I'd also recommend adding a QDevice on some external, unrelated host/vps/RPi/... to ensure that if one DC has problems the other node still is quorate.
https://pve.proxmox.com/pve-docs/chapter-pvecm.html#_corosync_external_vote_support

Also it should be no problem to cluster the servers via private ip addresses and manage them using the webinterface on public ip addresses, right ?
No, that's not an issue, the API and the cluster stack are two complete different services.

If I cluster the 2 machines and then find out that it was not a good idea to do so, ist there an easy way to "decluster" the servers again ?
Well, it's documented and normally works out ok, but it's not "just press a button" easy:
https://pve.proxmox.com/pve-docs/chapter-pvecm.html#pvecm_separate_node_without_reinstall