Complete Guide to Setting Up iSCSI Shared Storage with Ubuntu Server and Windows Client

This guide walks you through setting up an iSCSI target on an Ubuntu server and connecting a Windows machine as an iSCSI client. The process includes configuring the iSCSI service, preparing the disk, and connecting it to Windows. This setup is optimized for single-client use to avoid data corruption.

Prerequisites

• Ubuntu Server with an additional disk (/dev/sdb1) ready to use.
• Windows 10/11 machine as the client.
• Optional but recommended: Tailscale installed for secure access.
• Sudo privileges on the Ubuntu server.

Step 1: Prepare the Disk on the Ubuntu Server

Check if the additional disk is available:

lsblk

Ensure the disk is not mounted and has no active partitions.

Create a new filesystem (ext4):

sudo mkfs.ext4 /dev/sdb1

Create a mount point and mount the disk:

sudo mkdir -p /mnt/shared_storage
sudo mount /dev/sdb1 /mnt/shared_storage

Add the disk to /etc/fstab for automatic mounting at startup:

echo "/dev/sdb1 /mnt/shared_storage ext4 defaults 0 0" | sudo tee -a /etc/fstab

Step 2: Install and Configure TGT for iSCSI

Install the TGT package:

sudo apt update
sudo apt install tgt -y

Create an iSCSI target configuration file:

sudo nano /etc/tgt/conf.d/iscsi.conf

Add the following content:

<target iqn.2024-11.local.server:sharedstorage>
    backing-store /dev/sdb1
    initiator-address 100.0.0.0/8
    incominguser iscsi-user StrongPass123
    outgoinguser iscsi-target AnotherPass456
</target>

Restart the TGT service to load the configuration:

sudo systemctl restart tgt

Verify the iSCSI target status:

sudo tgtadm --mode target --op show

Ensure the LUN is configured correctly: If LUN 0 is set to controller, add another LUN:

tgtadm --mode logicalunit --op new --tid 1 --lun 20 --backing-store /dev/sdb1

Verify the LUN is configured as a disk.

Step 3: Connect to the iSCSI Target from Windows

Open the iSCSI Initiator on Windows:

• Press Win + S, search for iSCSI Initiator, and open the tool.
• If prompted to enable the service, click Yes.

Discover the iSCSI target:

• Go to the Discovery tab and click Discover Portal.
• Enter the Tailscale IP address of your Ubuntu server (e.g., 100.x.x.x) and click OK.

Connect to the iSCSI target:

• Switch to the Targets tab.
• Select the target (e.g., iqn.2024-11.local.server:sharedstorage) and click Connect.
• In the Advanced settings:
  • Enter the CHAP credentials:
    • Username: iscsi-user
    • Password: StrongPass123
  • Click OK to connect.

Detect the disk:

• Go to the Volumes and Devices tab.
• Click Auto Configure to detect the new disk.

Step 4: Initialize and Format the Disk in Windows

Open Disk Management:

• Press Win + R, type diskmgmt.msc, and press Enter.

Initialize the disk:

• A pop-up should prompt you to initialize the new disk.
• Select GPT (GUID Partition Table) and click OK.

Create a new volume:

• Right-click on the unallocated space and choose New Simple Volume.
• Follow the wizard to format the disk with NTFS.
• Assign a drive letter (e.g., D:) and label the disk (e.g., SharedStorage).

Verify the disk is accessible:

• Open File Explorer (Win + E) and ensure the new disk is listed.

Optional: Automatically Reconnect at Startup

• Open the iSCSI Initiator and navigate to the Targets tab.
• Select your target and click Properties.
• Check the option Add this connection to the list of Favorite Targets.
• Click OK.

Important Notes

• Single-client only: Do not connect multiple machines to the same iSCSI target without a cluster filesystem, as it can cause data corruption. For multi-client access, consider using NFS or SMB.

Conclusion

You have successfully set up iSCSI shared storage between an Ubuntu server and a Windows client. The disk behaves like a locally attached storage device on the Windows machine.

Tip: This setup can also be used for high-speed external storage, such as for storing Xbox games via iSCSI.