With DRBD you are stuck with 2 nodes and OCFS2 has given me nothing but head aches, at least in trying to getting it to work in CentOS 6. Apparently Oracle is "

With DRBD you are stuck with 2 nodes and OCFS2 has given me nothing but head aches, at least in trying to getting it to work in CentOS 6. Apparently Oracle is "forcing" people to use their RHEL clone or at least their kernel to get OFCS2. When I had to use DRBD I went with CLVM. Having said that, starting with v3.4.0 gfapi can be used if your Qemu supports it (it's the case with CentOS 6.4+ or Ubuntu 14.04), therefore bypassing the FUSE layer. This should give you an improved performance.