How to Set Up Offsite VM Replication with Proxmox for Disaster Recovery?

When Proxmox takes a backup, it uses snapshots but only briefly suspends the VM. Just make sure that you have 'fleecing' set up in your backup job; otherwise, write IO can get slowed down by the backup target. Proxmox keeps a bitmap of all the blocks a VM has written, which helps speed up backups, especially if the VM isn’t changing much. It's ideal to have a local PBS and another offsite for syncing; you can manage different retention policies for storage efficiency. Live restores are also an option with PBS, which is great in a disaster scenario, though performance might take a hit while it's happening. For the fastest failover option, direct storage replication is the way to go, but that requires ZFS. Ceph or LVM setups won't work for that.

We replicate our VMs onsite, but I think it would translate well to offsite as we use 10GbE links between data centers. We perform replication every minute to a matching node, and honestly, we haven’t seen any performance issues with this setup.

I'm in the same situation. If you're not using ZFS, there aren't many straightforward replication options available. Right now, PBS seems to be the best route if you want the ability to quickly spin up backups. Proxmox's datacenter manager has replication on their to-do list, and Veeam also has it as a feature request. I expect we'll see developments there soon. There are some Ceph replication options, but they can be quite complex.