OpenZFS Engineer — Storage Infrastructure, Pool Management & Production Support

Remote · Freelance · Part-time or Project-based / Consulting Summary We are looking for a senior OpenZFS engineer to help diagnose, stabilize, and optimize real-world storage environments running OpenZFS in production. This is not a greenfield setup role — it's focused on deep troubleshooting, pool health, and operational reliability. You'll work with real client cases through Hossted.com's open-source consulting practice, analyzing pool configurations, scrub reports, and performance metrics to identify issues and deliver practical, production-ready solutions. What You'll Work On: · Investigating pool degradation, checksum errors, and vdev failures across open-source deployments managed via Hossted.com. · Diagnosing I/O bottlenecks, ARC/L2ARC pressure, and cache hit ratio issues under load. · Reviewing and optimizing ZFS configurations — recordsize, compression, deduplication, and prefetch settings. · Analyzing scrub and resilver performance, snapshot management, and send/receive workflows. · Reviewing dataset hierarchy, quota configurations, and delegation setups. · Supporting OpenZFS upgrades, pool migrations, and feature flag transitions for Hossted.com clients. Requirements: · Proven hands-on experience operating OpenZFS in production environments (Linux or FreeBSD). · Strong understanding of ZFS internals — CoW mechanics, transaction groups, RAIDZ, and mirror vdev behavior. · Experience diagnosing pool faults, corrupted datasets, and failed resilver scenarios. · Familiarity with ARC tuning, ZIL/SLOG configuration, and L2ARC sizing. · Ability to troubleshoot using zpool status, zfs get, iostat, and system logs. · Comfortable working with open-source technologies in diverse client environments. · Strong debugging and root-cause analysis skills. · Strong written and spoken English — you will communicate directly with Hossted.com clients. Nice to Have: · Experience with open-source systems built on top of OpenZFS - TrueNAS, Proxmox, or ZFS-on-Linux (ZoL). · Familiarity with replication and disaster recovery using ZFS send/receive. · Experience with containerized or virtualized storage environments (Docker, KVM, bhyve). · Monitoring background - Prometheus ZFS exporter, Grafana, or equivalent for pool observability. · Basic DevOps / automation skills (Ansible, Terraform) About Hossted: Hossted is a U.S.-based company working with 300+ open-source technologies. We help companies solve complex technical issues through expert consulting - fast, practical, and hands-on. This role is part of our open-source expert network, supporting clients who run OpenZFS as a critical component of their open-source storage infrastructure. Why This Role Is Interesting: · Work on real production storage issues across Hossted.com's open-source client base - not routine pool setups · Flexible, fully remote consulting format · No long meetings - focus on solving real technical problems · Exposure to diverse open-source architectures and ZFS-dependent storage ecosystems. Best Fit: Senior engineers with a passion for open-source technologies who enjoy digging into storage system behavior, understand copy-on-write filesystem mechanics, and can resolve complex data integrity and performance issues in production environments. To Apply: Please include a brief note describing an OpenZFS environment you have supported: pool topology, approximate storage scale, operating system, and any significant incidents, data recovery operations, or performance improvements you have delivered.