Native ZFS VDEV for Object Storage (OpenZFS Summit)

Summary

We presented MayaNAS and MayaScale at OpenZFS Developer Summit 2025 in Portland, Oregon. The centerpiece of our presentation: objbacker.io—a native ZFS VDEV implementation for object storage that bypasses FUSE entirely, achieving 3.7 GB/s read throughput directly from S3, GCS, and Azure Blob Storage. Presenting at OpenZFS Summit The OpenZFS Developer Summit brings together the core developers and engineers who build and maintain ZFS across platforms. It was the ideal venue to present our approach to cloud-native storage: using ZFS's architectural flexibility to create a hybrid storage system that combines the performance of local NVMe with the economics of object storage. Our 50-minute presentation covered the complete Zettalane storage platform—MayaNAS for file storage and MayaScale for block storage—with a deep technical dive into the objbacker.io implementation that makes ZFS on object storage practical for production workloads. The Cloud NAS Challenge Cloud storage economics present a fundamental problem for NAS deployments: $96K/year 100TB on EBS (gp3) $360K/year 100TB on AWS EFS The insight that drives MayaNAS: not all data needs the same performance tier. Metadata operations require low latency and high IOPS. Large sequential data needs throughput, not IOPS. ZFS's special device architecture lets us place each workload on the appropriate storage tier. ZFS Special Device Architecture: Metadata and small blocks (<128KB) on local NVMe SSD. Large blocks (1MB+) streamed from object storage. One filesystem, two performance tiers, optimal cost. objbacker.io: Native ZFS VDEV for Object Storage The traditional approach to ZFS on object storage uses FUSE-based filesystems like s3fs or goofys to mount buckets, then creates ZFS pools on top. This works, but FUSE adds overhead: every I/O crosses the kernel-userspace boundary twice. objbacker.io takes a different approach. We implemented a native ZFS VDEV type (VDEV_OBJBACKER) that communicates directly with a userspace da...