TrueNAS ZFS-over-iSCSI Plugin for Proxmox VE

A Proxmox VE storage plugin that manages ZFS-over-iSCSI volumes on TrueNAS (CORE and SCALE) through the TrueNAS REST API — no SSH-based LUN management, no iscsiadm scripting.

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Table of Contents

• How It Works
• Compatibility
• Prerequisites
• Installation
• Configuration
• Upgrading
• Uninstalling
• Troubleshooting
• Contributing
• Support the Project
• License

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How It Works

Proxmox VE's built-in ZFS-over-iSCSI storage type uses SSH to manage LUNs on the storage server. This plugin replaces that SSH-based management layer with direct calls to the TrueNAS REST API, giving you:

• API token (Bearer) or username/password authentication
• Automatic TrueNAS API version detection (v1 and v2)
• Support for both TrueNAS CORE and TrueNAS SCALE
• Proper rollback when operations fail (no dangling iSCSI extents)

Note: Proxmox still uses iscsiadm to connect and disconnect the iSCSI session on the Proxmox host itself — that part is handled by the core Proxmox code and does not require SSH. The SSH keys documented in the Proxmox ZFS-over-iSCSI wiki are still required for the ZFS pool listing step.

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Compatibility

Plugin Version	Proxmox VE	TrueNAS CORE	TrueNAS SCALE
3.x (upcoming)	8.x	13.0-U6+	23.10 (Cobia)+, 24.04 (Dragonfish)+
2.x (current stable)	7.x, 8.x	11.3+	22.02+

Check the Releases page for the specific Proxmox and TrueNAS versions tested against each release.

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Prerequisites

Before installing, ensure the following are in place on your Proxmox VE node:

1. SSH keys configured between Proxmox and TrueNAS — required for ZFS pool listing by the Proxmox core (see the Proxmox wiki, section starting with mkdir /etc/pve/priv/zfs).

2. On TrueNAS, an iSCSI target and initiator group must exist and be configured. The plugin manages extents and target-to-extent mappings, but the target itself must be pre-created.

3. On TrueNAS SCALE or TrueNAS CORE 13+, generate an API key:

   • TrueNAS SCALE: System Settings → API Keys → Add
   • TrueNAS CORE: System → API Keys → Add

   Copy the key — you will need it during storage configuration in Proxmox.

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Installation

Stable Release

Add the repository and install:

# Import the GPG key
curl -fsSL https://dl.cloudsmith.io/public/ksatechnologies/truenas-proxmox/gpg.284C106104A8CE6D.key \
  | gpg --dearmor \
  | tee /usr/share/keyrings/ksatechnologies-truenas-proxmox-keyring.gpg > /dev/null

# Add the repository
cat > /etc/apt/sources.list.d/ksatechnologies-repo.list << 'EOF'
deb [signed-by=/usr/share/keyrings/ksatechnologies-truenas-proxmox-keyring.gpg] \
  https://dl.cloudsmith.io/public/ksatechnologies/truenas-proxmox/deb/debian any-version main
EOF

# Install
apt update && apt install freenas-proxmox

Testing / Beta Release

For early access to new features (may be unstable):

# Import the GPG key
curl -fsSL https://dl.cloudsmith.io/public/ksatechnologies/truenas-proxmox-testing/gpg.CACC9EE03F2DFFCC.key \
  | gpg --dearmor \
  | tee /usr/share/keyrings/ksatechnologies-truenas-proxmox-testing-keyring.gpg > /dev/null

# Add the repository
cat > /etc/apt/sources.list.d/ksatechnologies-testing-repo.list << 'EOF'
deb [signed-by=/usr/share/keyrings/ksatechnologies-truenas-proxmox-testing-keyring.gpg] \
  https://dl.cloudsmith.io/public/ksatechnologies/truenas-proxmox-testing/deb/debian any-version main
EOF

# Install
apt update && apt install freenas-proxmox

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Configuration

After installation, refresh your browser to load the updated Proxmox UI. Then add a new ZFS-over-iSCSI storage:

1. Navigate to Datacenter → Storage → Add → ZFS over iSCSI
2. Set iSCSI Provider to FreeNAS/TrueNAS API
3. Fill in the storage fields — see below for authentication options

Authentication: API Token (Recommended)

Field	Value
Portal	IP or hostname of your TrueNAS server
Target	The iSCSI target IQN
Pool	The ZFS pool name
Use SSL	Enabled (recommended)
API Host	Leave blank to use Portal IP, or specify a separate management IP
Use Token Auth	Enabled
API Token	Paste the TrueNAS API key you generated

Authentication: Username / Password (Legacy)

Field	Value
Use Token Auth	Disabled
Username	TrueNAS API user (usually root)
Password	TrueNAS user password

Security note: Username/password authentication sends credentials on every API call. API token authentication is preferred and may be required in future TrueNAS releases.

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Upgrading

The package integrates with Proxmox VE's standard upgrade mechanism. On apt upgrade, the package will automatically re-apply any patches needed after a Proxmox VE update:

apt update && apt full-upgrade

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Uninstalling

apt remove freenas-proxmox

This removes the plugin and reverses all patches, returning your Proxmox VE installation to its unmodified state. Any storage configurations using this plugin should be removed from Proxmox before uninstalling.

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Troubleshooting

After install, the "FreeNAS/TrueNAS API" option is not visible

Refresh your browser (force-refresh with Ctrl+Shift+R or Cmd+Shift+R). The Proxmox UI JavaScript is cached aggressively.

Storage shows as unavailable / API connection fails

Check journalctl -f or /var/log/syslog on the Proxmox node — the plugin logs all API calls and errors with [FreeNAS::API::] prefixes.

Common causes:

• Wrong API host or portal IP
• SSL mismatch (try toggling SSL on/off)
• API token expired or revoked
• TrueNAS iSCSI service not running

Dangling extents on TrueNAS after a failed operation

If you see iSCSI extents in TrueNAS that are not associated with any target, they can be safely deleted from the TrueNAS UI. The v3.x plugin release adds automatic rollback to prevent this.

Filing a Bug Report

Please use the GitHub issue tracker and include the bug report template. Include relevant log lines from syslog (search for FreeNAS::).

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Contributing

Contributions are welcome. Please read CONTRIBUTING.md before opening a pull request.

For significant changes, open an issue first to discuss the approach.

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Support the Project

If this plugin saves you time, consider supporting its development:

• GitHub Sponsors: github.com/sponsors/TheGrandWazoo
• PayPal: Donate via PayPal

Donor support has funded a 4-node Proxmox cluster and TrueNAS test lab used for development and validation. See DONORS.md for a full list of donors.

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License

Copyright (c) 2020 KSA Technologies, LLC

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, version 3.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.