A couple of years ago, I staged a test environment using RHEL 5u1 with a few KVM guests that were provisioned with a direct LUN for use with Cluster Suite and resilient storage (GFS2). For whatever reason (on reflection, I may have overlooked the hypervisor’s virtio default setting for cache), the GFS2 filesystem would eventually “break” and leave it fencing guests. We had always run our clusters (dev-test-prod) on physical hosts before and since, so cluster configuration and operational understanding is not any issue.
We now have RHEV-M in place to begin a whole new provisioning process on newer RHEL 6 hypervisors with RHEL 6 guests. My question (or fear) before embarking into this space is how resilient is resilient storage (GFS2) on KVM guests now? Are there any pitfalls to avoid out there?
Robert Hurst, Caché Systems Manager