Earlier this year developers at LINBIT began working toward a goal of upstreaming ~15 years worth of their Distributed Replicated Block Device changes into the mainline Linux kernel. That major update has yet to land but sent out this week was a new patch series in preparing the trek toward introducing DRBD 9 support in the mainline kernel.

Distributed Replicated Block Device is the functionality to allow for mirroring block devices between multiple host systems via a kernel driver and combination of user-space software. DRBD aims for use cases from cloud computing to high availability clusters.

LINBIT has continued improving the out-of-tree DRBD kernel driver while the upstream code stagnated. This week's patches are prep changes in updating the existing DRBD 8.4 targeted code in the kernel to the DRBD 9 state. The series is mostly about restructuring the code to better align with the out-of-tree code organization. Plus raising various limits to match the values of DRBD 9. After these prep changes, hopefully the rest of the DRBD 9 patches for mainline won't be too far behind.

Distributed Replicated Block Device 9 supports replication up to 32 nodes, network load balancing, faster I/O performance, built-in quorum management, and other enhancements over DRBD 8.

These prep patches are out for review on the LKML.