Adding node running CTs to cluster

[ianux]

Hello,

I read in the PVE wiki that in order to add a node to a cluster, it shouldn't run any VM, because of potential VMID conflict.

But, thinking that I could join the cluster at anytime, I was very careful about giving a unique VMID to all my CTs, regardless of the node they was running on.

So, with that in mind, how could I force a node to join a cluster ? Is shutting down all VMs enough ? Is it even possible ?

I could migrate all CTs by hand but it is a bit painful because when using vzdump, the configuration of the CT is lost and I have to recreate it by manually giving disk size, amount of RAM, number of CPU, IP addresses in the process.

 

[t.lamprecht]

Yes you can add it, it should probably not be done on a production system as if you missed something and there is a collision you may get some problems.

If you are sure there are no such problems you could use the following command from the node you want to add:

pvecm add --force <IP-from-cluster-member>

Is shutting down all VMs enough

This shouldn't be needed, the VMs are not affected by this, "only" the cluster filesystem (pmxcfs).

ause when using vzdump, the configuration of the CT is lost

That's not true, at least on newer Versions from PVE, AFAIK.

Although I tried such scenarios it was always on test systems where I did not really cared about data loss, so I do not really want take any responsibility for this .

 

[dietmar]

But, thinking that I could join the cluster at anytime, I was very careful about giving a unique VMID to all my CTs, regardless of the node they was running on.

A cluster join also overwrite the storage definition and other configuration files. So you will have real trouble if your VMs depends on those files...