You need 3 identical Proxmox VE servers (V4.0 or higher) with the following extra hardware:
- Ability to live migrate running machines without downtime in a few seconds WITHOUT the need of SAN (iSCSI, FC, NFS) as the data is already on both nodes.
- LXC containers can use DRBD9 storage
https://pve.proxmox.com/wiki/DRBD 舊
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How to build a two node Proxmox cluster with native ZFS (ZFS on Linux) and DRBD support.
http://acidrop.biz/wp/?p=559