Yes, you need to read:
http://pve.proxmox.com/wiki/DRBD
http://pve.proxmox.com/wiki/Two-Node_High_Availability_Cluster
http://pve.proxmox.com/wiki/Proxmox_VE_2.0_Cluster (if you have only 2 PVE Nodes: expected_votes="1")
And i don't remember where is in the forum:
- Manual fence (don't use fence device if you have only two Nodes)
- Shrink the PVE partition for get free space for drbd partition.
- Recomendation: Use 2 NICs 1 Gb/s to make Bonding "balance-round robin" for each DRBD Volume if you don't need more of 220 MB/s for write to HDD in each DRBD Volume, otherwise you can use NICs of 10 Gb/s instead of 1 Gb/s
Note: For DRBD partition, is better to have 2 partitions DRBD, and in each DRBD partition run VMs in a PVE Node, of this mode, if you have problems with a Node or with a replication DRBD (for example: the Network cables were cut), will be more easy to do resyncronization of the DRBD Volume (and can do it online) when the Node returns to PVE cluster or the system of replication is working again
I have these configurations and works very well in production enviroments