ZFS on Proxmox: Complete Storage Guide

Last updated: May 5, 2026 | Reading time: 11 minutes

Why ZFS?

ZFS is more than a filesystem—it's a volume manager with:

✅ Data integrity (checksums)
✅ Snapshots (instant, space-efficient)
✅ Compression (saves space, can improve speed)
✅ RAID (software, flexible)
✅ Self-healing (detects and fixes corruption)

RAID Levels

| Level | Min Disks | Usable | Fault Tolerance | |-------|-----------|--------|-----------------| | RAID0 | 2 | 100% | None | | RAID1 | 2 | 50% | 1 disk | | RAID10 | 4 | 50% | 1 per mirror | | RAIDZ1 | 3 | 67% | 1 disk | | RAIDZ2 | 4 | 50% | 2 disks | | RAIDZ3 | 5 | 40% | 3 disks |

Recommendation: RAIDZ2 for homelabs. Best balance of capacity and safety.

Installation

During Proxmox Install

Select "ZFS (RAID0)" or your preferred level
Choose disks
Set compression: lz4 (fast) or zstd (better ratio)
Set ashift: 12 (for 4K sector drives)

After Installation

# Create pool
zpool create -o ashift=12 tank mirror /dev/sda /dev/sdb

# Create dataset for VMs
zfs create tank/vms

# Add to Proxmox
pvesm add zfspool tank -sparse 1

Compression

# Check compression
zfs get compression tank

# Enable compression
zfs set compression=zstd tank

# Compression ratios
# lz4: 1.5-2x (fastest)
# zstd: 2-3x (good balance)
# gzip: 3-4x (slowest)

Recommendation: zstd for most use cases.

Snapshots

# Create snapshot
zfs snapshot tank/vms@before-update

# List snapshots
zfs list -t snapshot

# Restore snapshot
zfs rollback tank/vms@before-update

# Delete snapshot
zfs destroy tank/vms@before-update

Automated Snapshots

# Install sanoid
apt install sanoid

# Configure
nano /etc/sanoid/sanoid.conf

Example config:

tank/vms:
    hourly = 4
    daily = 7
    weekly = 4
    monthly = 6

ARC (Cache) Tuning

ZFS uses RAM as cache (ARC). Default: 50% of RAM.

# Check ARC usage
arc_summary

# Limit ARC to 8 GB
echo 8589934592 > /sys/module/zfs/parameters/zfs_arc_max

# Make permanent
echo "options zfs zfs_arc_max=8589934592" > /etc/modprobe.d/zfs.conf

Rule: ARC = 25-50% of RAM for homelabs.

Scrub (Data Integrity Check)

# Start scrub
zpool scrub tank

# Check progress
zpool status tank

# Schedule monthly
echo "0 0 1 * * root zpool scrub tank" >> /etc/crontab

Best Practices

Use ECC RAM if possible (not required but ideal)
Don't mix drive sizes in same vdev
Don't use RAIDZ3 unless you have 8+ drives
Always have backups (ZFS is not a backup)
Monitor SMART data for drive health

ZFS is the best filesystem for Proxmox. The data integrity alone is worth it.