Proxmox iSCSI Target with Synology Storage (Complete Setup Guide)

If you’re looking to scale your home lab or small business infrastructure, learning how to configure a Proxmox iSCSI Target with Synology Storage is a critical skill. Proxmox VE is a world-class virtualization platform, but it truly shines when paired with reliable, high-speed shared storage. In this guide, we’ll walk you through the process of connecting Proxmox to a Synology NAS via iSCSI, ensuring your virtual machines have the performance and redundancy they need to thrive.

Why Use iSCSI for Proxmox Shared Storage?

While NFS is easy to set up, iSCSI (Internet Small Computer Systems Interface) offers block-level access, which often results in superior performance for database-heavy virtual machines. By utilizing a Proxmox iSCSI Target with Synology Storage, you enable features like live migration and high availability (HA) across your Proxmox cluster. This ensures that even if one node fails, your workloads can seamlessly transition to another node with zero data loss. This level of reliability is essential for building Safe AI Workflows where uptime and data integrity are paramount.

Prerequisites

Before you attempt to Proxmox iSCSI Target with Synology Storage, ensure you have the following components ready:

Proxmox VE 7.x or 8.x: Installed and reachable on your network.
Synology NAS: Running DSM 6.2 or later (DSM 7.x recommended).
Dedicated Storage Network: Ideally, a separate VLAN or physical switch for iSCSI traffic to avoid congestion with management or VM traffic.
SAN Manager (Synology): Installed and configured on your NAS.

Step 1: Configuring the Synology iSCSI Target

The first step to Proxmox iSCSI Target with Synology Storage happens on your Synology NAS. Open the ‘SAN Manager’ and navigate to the ‘iSCSI’ tab. Create a new Target and associate it with a LUN (Logical Unit Number). We recommend using ‘Thick Provisioning’ if performance is your top priority, as it pre-allocates the space and reduces disk fragmentation over time. Ensure you enable CHAP authentication for an extra layer of security, especially if your storage network isn’t completely isolated.

Step 2: Connecting Proxmox to the Synology Target

Once the target is ready, log in to your Proxmox web interface. Go to ‘Datacenter’ > ‘Storage’ > ‘Add’ > ‘iSCSI’. Here, enter a unique ID, the IP address of your Synology NAS, and the IQN (iSCSI Qualified Name) you created in the previous step. If you enabled CHAP, provide the credentials here as well. This is the moment your Proxmox node discovers the Proxmox iSCSI Target with Synology Storage. This process is very similar to how we Set Up n8n on Proxmox for local automation—reliability starts with the storage layer.

Step 3: Creating an LVM over iSCSI

After Proxmox has successfully connected to the Proxmox iSCSI Target with Synology Storage, you’ll see a new block device. However, to actually use it for multiple VMs, you need to create a Volume Group. Go to ‘Add’ > ‘LVM’ in the storage menu, select your iSCSI target as the base provider, and give your new shared storage pool a name. This LVM layer allows Proxmox to manage individual virtual disks efficiently across the shared iSCSI connection.

Troubleshooting Common iSCSI Issues

Setting up a Proxmox iSCSI Target with Synology Storage can sometimes result in ‘Target Not Found’ errors. Here are the most common solutions:

1. Network Timeouts and MTU Mismatches

If you’re using Jumbo Frames (MTU 9000), ensure every device in the path—Proxmox, the switch, and the Synology NAS—is configured identically. A single mismatch will cause packet drops and extremely poor iSCSI performance. Most Proxmox iSCSI Target with Synology Storage failures are actually networking failures in disguise.

2. IQN Mismatches and ACLs

Synology targets often have Access Control Lists (ACLs). Ensure that your Proxmox node’s initiator IQN (found in /etc/iscsi/initiatorname.iscsi) is added to the ‘Allowed’ list in the Synology SAN Manager. Without this, the connection will be refused even with correct CHAP credentials.

Conclusion

Building a Proxmox iSCSI Target with Synology Storage infrastructure is one of the best upgrades you can make to your Proxmox cluster. It unlocks the true power of enterprise virtualization, allowing for seamless growth and high availability. For deeper technical specifications on iSCSI protocols, refer to the Official Proxmox iSCSI Wiki. Now that your storage is solid, you’re ready to host even the most demanding applications with confidence!