DRBD is a virtual block device driver for Linux and is on the kernel (drbd-8.4), which has seen massive improvements out-of-tree (drbd-9.2). We are preparing to upgrade the in-tree version to 9.2. However, as of writing this proposal, it is unknown if that effort will be successful by the time of the presentation.

The out-of-tree DRBD is the data plane behind LINSTOR and, with that, the workhorse behind Piraeus Datastore (for Kubernetes) and plenty of other integrations to virtualization orchestrators such as Apache CloudStack, OpenNebula, OpenStack (cinder), Proxmox VE, XCP-ng, and oVirt.

This session will inform users of DRBD 9.2 in such configurations. I will explain in detail how quorum works in the context of DRBD. I will discuss DRBD’s meta-data, the activity log, and the change tracking bitmap. This knowledge will help the listener architect high-performing and highly available data storage for their next virtualization or container project using standard off-the-shelf hardware and open-source software. Additionally, I will discuss the effects of a fully hyper-converged architecture vs. a disaggregated architecture as it relates to the previously presented information.