Migration from VMware vSAN to Proxmox CEPH

[PoschMox93]

Hello,

I wanted to ask if anyone has migrated a 4-node VMware vSAN cluster to Proxmox Ceph without downtime and additional hardware.
My plan would be:

• Remove 2 of the 4 nodes from vSAN (RAID-1)
• Install a Proxmox 2-node Ceph cluster (min. 2 / 2 replicas, 2 MONs, 2 MGRs)
• Migrate/restore VMs from VMware to Proxmox
• Add the remaining nodes to the Proxmox cluster
• 4-node Ceph cluster with 3 MONs + 2 MGRs (min. 2 / 3 replicas)
• If required: Split into a 2+2 stretched cluster with a tiebreaker node across three rooms (5 MONs, 3 MGRs, min 2 / 4 replicas) -> replicated_room CRUSH Rule

Any considerations? Have someone have done this is in a real world sceneario?

Your feedback would be very helpful.
Thanks!

 

[gurubert]

This will only work if the current VM workload only needs less than half of the available hardware resources.

 

[robertlukan]

I would say it is possible if you are willing to take quite some risk while migrating VMs as there is no room for redundancy. Ceph does not like 2 monitors, so you will need to trick it. It is possible, but maybe not the best approach. Proxmox does not like 2 node cluster so if you lose one node you will not be able to start the VMs, so you would need another physical hardware, even Raspberry PI is fine, to avoid this situation.

You cannot use vSAN storage to import VMs to Proxmox. So you will need a temporary storage, maybe NFS server.

Without downtime, that is impossible. You will need at least some downtime.