Setting up TrueNAS iSCSI with ZVOLs (VMWare)

Summary #

Due to some issues with VMFS and how it wants the Logical and Physical Block Sizes to be configured, it requires very specific settings.

Here you will find a basic overview of how to setup a VMWare Compatible iSCSI Target on TrueNAS.

Recommended Block Size Settings: VMWare 7 with VMFS6 #

• BS (Block Size): 64KiB
• LBS (Logical Block Size): 512

Global Configuration #

First and foremost, you must configure your IQN Name.

To do this go to the Sharing → Block Sharing (iSCSI) → Target Global Configuration menu and in your Base Name field enter an IQN Name according to this format (See Also: RFC3720).

The domain must be reversed and it may optionally contain a serial number

Format: iqn.YYYY-MM.com.example.host Examples:

• iqn.2023-11.com.example.truenas-01
• iqn.2023-11.com.example.truenas-01:ABCD1234

Creating the ZVOL for the iSCSI Target #

To create the corresponding ZVOL in our Dataset go to Storage → Pools Click on the three vertical dots button and use the Add ZVOL Option.

Recommended ZVOL Parameters #

• ZVOL Name: LUN0
• Size: 100GB
  • Choose whatever size you want, it may be up to 80% of your ZFS Pool. This may be overriden clicking the Force Size checkbox.
• Synchronization: Standard
• Compression Level: LZ4
• Block Size (In Advanced Options): 64KiB

Everything else can be left on defaults.

Setting up the iSCSI Service #

Important: Ensure the iSCSI Service is enabled and auto-start is activated.

Creating the iSCSI Portal #

After creating our ZVOL we must create the iSCSI Portal.

1. Go to Sharing → Block Sharing (iSCSI) → Portals.
2. Click the ADD button.
3. Setup a Portal with the following settings:

• Description: Portal0
• Authentication Method and Group: To your liking (default: NONE)
• Discovery Authentication Group: N/A
• IP Addresses: 0.0.0.0 (or whatever IPs you’ve assigned to your SAN, 2 IPs recommended for multipathing).

Creating the iSCSI Initiator Groups #

In the Initiator Groups tab you must create an entry to authorize Initiators.

1. Go to Sharing → Block Sharing (iSCSI) → Initiator Groups.
2. For testing purposes you may create one that allows any host, or restrict it to a subnet.

Creating the iSCSI Target #

To create an iSCSI Target you may do the following.

1. Go to Sharing → Block Sharing (iSCSI) → Targets.
2. Add an entry with the following recommended parameters:

• Basic Info
  • Target Name: p0-target0
• iSCSI Group
  • Portal Group ID: {$YOUR_PORTAL_GROUP_ID}
  • Initiator Group ID: {$YOUR_IGRP_ID}
  • Authentication Method: NONE
  • Authentication Group Number: N/A

Creating the iSCSI Extent #

After creating the target we must associate it to an Extent.

1. Go to Sharing → Block Sharing (iSCSI) → Extents.
2. Create an Entry with the following recommended parameters:

• Basic Info
  • Name: p0-t0-extent0
• Type
  • Extent Type: Device
  • Device: zfspool/dataset/LUN0
  • LBS (Logical Block Size): 512
• Compatibility
  • LUN RPM: SSD/7200k/5400k/etc. (Depends on your hardware)

Creating the iSCSI Associated Targets #

Finally we can create an Associated Target to match to our ZVOL to a LUN ID.

1. Go to Sharing → Block Sharing (iSCSI) → Associated Targets.
2. Create an Entry with the following recommended parameters:

• Target: p0-target0
• LUN ID: 0
• Extent: p0-t0-extent0

You may now add and test the iSCSI Target to your VMWare/ESXi Configuration.