Hello, in my environment we are currently undergoing an IP re-scheme so I am moving all of my servers to a new VLAN, I want to migrate my Proxmox cluster to the new IP scheme. At first we tried simply changing the ip of one of the hosts after migrating VMs off of it. We noticed the cluster lost connectivity with that node. So we figured it must be more complicated.
So I began researching the process for doing this, and that is when I came across the instructions on this page. https://pve.proxmox.com/wiki/Proxmox_VE_4.x_Cluster
On here I learned a few things, the most surprising though was how complicated something as simple as a new IP is. "Changing the hostname and IP is not possible after cluster creation" So we tried moving one node at a time following the instructions here, you will find that what we tried is flawed and ill explain why I realize this now below.
So now it came time to migrate, to give you a brief layout we have 3 cluster nodes. So I started by removing the currently "unused" node from the cluster. Deleted it from the cluster, rebuilt it, put it on the new-subnet new hostname. Tried to add it to the existing cluster, so then I could migrate the next node. but it failed, we received a corosync.service failed error, and while the existing cluster was aware of the new node it could not connect to it. Had a red x on the new node.
So I did some more reading, I see now that because they use multicast communication they all need to be on the same network, I suspect this is why it failed. However knowing that makes this migration difficult, the reason I am posting here is I am trying to find out what the best way is to migrate an existing cluster to a new IP subnet is?
My assumption is that I would effectively have to offline everything my nodes and guests. Leave one primary node up and running and migrate it to the new network. Re-ip my guests on that node, then rebuild the other two nodes, put them on the same network and join them to the primary node I started with as a cluster. However any suggestions or best practices would be appreciated.
So I began researching the process for doing this, and that is when I came across the instructions on this page. https://pve.proxmox.com/wiki/Proxmox_VE_4.x_Cluster
On here I learned a few things, the most surprising though was how complicated something as simple as a new IP is. "Changing the hostname and IP is not possible after cluster creation" So we tried moving one node at a time following the instructions here, you will find that what we tried is flawed and ill explain why I realize this now below.
So now it came time to migrate, to give you a brief layout we have 3 cluster nodes. So I started by removing the currently "unused" node from the cluster. Deleted it from the cluster, rebuilt it, put it on the new-subnet new hostname. Tried to add it to the existing cluster, so then I could migrate the next node. but it failed, we received a corosync.service failed error, and while the existing cluster was aware of the new node it could not connect to it. Had a red x on the new node.
So I did some more reading, I see now that because they use multicast communication they all need to be on the same network, I suspect this is why it failed. However knowing that makes this migration difficult, the reason I am posting here is I am trying to find out what the best way is to migrate an existing cluster to a new IP subnet is?
My assumption is that I would effectively have to offline everything my nodes and guests. Leave one primary node up and running and migrate it to the new network. Re-ip my guests on that node, then rebuild the other two nodes, put them on the same network and join them to the primary node I started with as a cluster. However any suggestions or best practices would be appreciated.
