Can I modify the protocol of each DRBD9 disk image individually?

[keaniny]

Hi,

I've just set up a new 2-node proxmox 4.x cluster with DRBD9 successfully. The two nodes are located in different datacenters, connected by a openvpn tunnel with 2Mb bandwidth.

The default protocol configured after following the DRBD9 howto is "C". To boost the performance, is it possible to:

1. modify the protocol of each DRBD9 disk resource to "A" or "B", individually? Is the changes persist after reboot?
2. insert the proxy stanza into the DRBD9 disk resource, and modify the connection peers, if DRBD-proxy is get into the play?

Thanks in advance.