LINBIT DRBD vs Longhorn

LINBIT DRBD is open-source distributed replicated block storage software for Linux, used in high-availability setups. Its kernel driver mirrors writes to one or more peer nodes; in synchronous mode, a write completes only after local and peer storage completion events. Reads can be served locally without network traffic, and the data path avoids user-space components. DRBD combines the kernel driver with user-space management applications and shell scripts, and its command-line interface can manage large clusters without relying on cloud, virtualization, or container platforms. It supports TCP/IP and RDMA/Verbs transports, including InfiniBand, iWARP, and RoCE. The DRBD 9 guide documents TLS encryption for TCP transport. LINBIT also offers WinDRBD for Windows and says its subscriptions integrate with Kubernetes and other major platforms. The open-source community version is free; LINBIT Starter is $1,000 a year, starting from $1,000 for two nodes. The company is headquartered in Vienna, Austria.

Longhorn is a free, open-source distributed block storage system for Kubernetes. It replicates storage across nodes and data centers to increase availability, with V1 replicated, V2 replicated and V2 sharded with erasure coding volume types. Teams can schedule recurring snapshots and backups to NFS or S3-compatible secondary storage, and create disaster recovery volumes for recovery in a second Kubernetes cluster. A GUI dashboard is included, and the management UI is described as free. The software stack can be upgraded without disrupting running storage volumes. Installation options include kubectl, Helm, Fleet, Flux and ArgoCD. Longhorn supports mTLS for securing and encrypting gRPC communication between its control and data planes, but mTLS is disabled by default. Components need root access with privileged permissions for volume operations and management. Backups require an NFSv4 client, while ReadWriteMany volumes require NFSv4.1. Longhorn runs on Linux and supports API, web and self-hosted use. It is a CNCF incubating project; SUSE Storage is described as a Longhorn-based distribution with additional support, security, lifecycle management and certified integrations.