Exploring High-Availability in Proxmox: Centralized Storage with Local SSD Failover

[Jhou]

Currently, I'm running a Proxmox server with centralized storage, contracted at a datacenter. I'm considering migrating to a high-availability (HA) setup with three servers and would like to know if it’s possible to configure one of the servers with local SSDs. The idea is that, in case of a failure in the centralized storage, this server with local SSDs could automatically take over the VMs and keep the services running.

Has anyone configured something similar or have recommendations on the feasibility of this setup, especially regarding replication and failover between centralized storage and local SSDs?

Thanks in advance for any help and guidance!

 

[ubu]

You can use ceph, so all your proxmox nodes are also storage nodes. you need at lease 3 nodes, 2 have to be online for your storage to be accessible. More nodes are better. You need fast network for your ceph storage (10gbit minimum, 25gbit, 40gbit or 100gbit recommended.)

 

[jdancer]

Another option is ZFS replication at intervals. It won't be real-time replication like Ceph though. I've ran Ceph using 1GbE full-mesh broadcast network on 14-year old servers and it worked surprisingly well. I don't recommend it for production though.

 

[LnxBil]

Has anyone configured something similar or have recommendations on the feasibility of this setup, especially regarding replication and failover between centralized storage and local SSDs?

Replication does only work if you're running ZFS, which is normally not case with off-the-shelf-central-storage, so the only viable option for you is to script something together that replicates the data for you. IMHO, the only easy to script and consistent option is to have a PBS running and continously backup and restore the most important VMs.

Is your centralized storage not HA? Every SAN i ever saw had two heads and nowadays almost all of them have replication built-in and used with some kind of transparent failover technology, so that you have four heads of which you only need one.