How to Master ZFS on Proxmox: Datasets, Snapshots, and ARC Tuning

A seasoned sysadmin with over a decade of experience has published a technical guide on running ZFS effectively within Proxmox VE, the open-source virtualization platform that uses OpenZFS by default. The article explains how ZFS organizes storage through pools and datasets rather than traditional volume managers like LVM, and warns that poor planning at setup time can lead to costly structural changes later. It recommends creating separate datasets for VM images, container storage, and backups instead of stacking everything under a single root pool. The guide also addresses a common pain point: ZFS's Adaptive Replacement Cache can consume large amounts of RAM and degrade virtual machine performance if left untuned. The author emphasizes that careful upfront configuration of datasets, snapshots, and ARC limits is essential for stable, production-grade deployments.