Seeking advice for 2 node cluster

[nakata720]

Hello everyone !

I am setting up a proxmox cluster with two nodes. I know that the cluster must be with at least 3 nodes but I for now that is what I can afford.

I have two identical servers each of them with two storage devices in raid 1 - 256GB/198GB (The operating system is installed on the raid)
The raids are created in the bios of the machines.

Up to now I have already created the cluster and gave the primary node two votes :


Now I want to create local storage for the two nodes to be able to replicate the (future) CTs and VMs. I have chosen the ZFS option but when I try to create one I get this :


Here are my disks : node 1

node 2


What did I miss guys ? I am sorry for the question but I am still a newbie

Thank you !

 

[krikey]

Hardware RAID provided by your PERC is not compatible with software RAID provided by ZFS.

You're trying to build RAID on an already RAIDed system.

 

[Philipp Hufnagl]

Using ZFS on top of a hardware raid is not recommended as mentioned in the documentation here.

I would recommend either disabling the hardware raid in the bios or choosing an other file system

 

[nakata720]

Thank you very much for your response guys !
So how can I configure the storage for the 2 nodes and enable the replication ?
I want to stay with the hardware raid if it's possible. Should I configure Ceph instead ?

 

[Philipp Hufnagl]

No Ceph is not a good idea with hardware raid either and also needs 3 discs to work properly.

If you have a hardware raid, your hardware is managing that part. Just go for plain ext4 or xfs then

 

[Dunuin]

And replication relies on ZFS. And with only 2 nodes you need a VM on a NAS or some cheap SBC/Thin-Client as a qDevice to act as a third voter. Without that, if any of your 2 nodes will be unavailable, the other one will stop working too because of quorum loss.

I personally wouldn't create a cluster and run those two PVEs unclustered.

 

[mahshadows]

And replication relies on ZFS. And with only 2 nodes you need a VM on a NAS or some cheap SBC/Thin-Client as a qDevice to act as a third voter. Without that, if any of your 2 nodes will be unavailable, the other one will stop working too because of quorum loss.

I personally wouldn't create a cluster and run those two PVEs unclustered.

I have a cluster with 2 nodes, so when I turn off 1 for maintenance, the other also becomes unavailable. So to what you're saying, this is normal, right?

 

[Dunuin]

Yes, a cluster needs always 51+% of the votes or you will lose quorum.Two nodes and one node going down the votes will drop to 50% and the remaining node will stop working too. So you need 3 nodes or 2 nodes + qdevice for a total of 3 votes. So when one node goes down there are still 66% of votes available for the cluster to continue operating. Please read the full cluster article: https://pve.proxmox.com/wiki/Cluster_Manager