How to Connect FreeNAS iSCSI Disks to VMware vSphere (ESXi)

Connect FreeNAS iSCSI Disks VMware vSphere Having a setup like a data centre including VMware vSpehre (ESXi) server, NAS (Network Access Storage), iSCSI disks and several server VMs on a single (or couple of) PC is a wonderful way to learn and test computing. You can experiment all at your home PC before going to the production environment.  In this article, I show you how to connect FreeNAS iSCSI disks to VMware vSphere 4 (ESXi 4) Server. Though the server version is pretty old, most of the main steps remain the same for the latest versions.

For testing purpose with VMware ESXi server and iSCSI disks, we can’t buy physical NAS device or disturb existing production NAS. So, FreeNAS and VMware workstation is a good option to achieve this requirement.  I used VMware vSphere 4, FreeNAS and Windows 2008 R2 servers to install and test Exchange 2010 in the cluster.

The Majors Steps I Followed

1)      Installed VMware vSphere 4 (ESXi4) on VMware workstation.

2)      Installed FreeNAS in VMware workstation.

3)      Installed three Windows 2008 R2 Operating Systems on ESXi4 (one domain controller and two for Exchange cluster).

4)      Connected FreeNAS iSCSI disks to VMware ESXi4 and created Windows 2008 R2 clusters.

Sounds good, isn’t it? I have done these all on my single home computer.

In this article, I show you how to connect FreeNAS iSCSI disks as storage to VMware ESXi 4 vSphere server.

Steps to Connect FreeNAS iSCSI Disks to VMware vSphere (or ESXi)

1)      Install and configure VMware vSphere 4 (ESXi4) server. Read more here about steps.

2)      Install and configure FreeNAS iSCSI disks on VMware workstation or any other networked computer. Make sure VMware vSphere and FreeNAS can communicate via the network. Read more here about configuring iSCSI disks in FreeNAS.

In this example, I created 20GB iSCSI disk in FreeNAS and my final iSCSI setup screen shows as below.

Active iSCSI disks

3)      Now connect ESXi4 server by vSphere 4 client. Go to the configuration tab.

Configure Options

4)      Go to storage Adapters option. Don’t go to storage now, select Add storage and try to add Disk/LUN. Nothing will show up in next screen till you enable iSCSI adapter in Storage Adapters. So, Click on Storage Adapters and go to next screen.

5)      Click on iSCSI Software Adapter and click properties as shown below.

iSCSI Adapter Options

6)      By default iSCSI adapter is disabled in VMware vSphere (ESXi) server. Press the Configure button, select Enable and Press OK.

Enable iSCSI Adapter in vSphere

7)      Now again select iSCSI adapter and go to properties. After you enabled iSCSI adapter in the earlier steps, you could see the name now.

datastore vmware

Go to ‘Dynamic Discovery’ tab of the Properties. Press Add button.

8)      In ‘iSCSI Server’ type your FreeNAS server address where you setup FreeNAS iSCSI disks.


9)      Once successfully added, go to the ‘Static Discovery’ tab and make sure it detected the FreeNAS iSCSI disk.


10)   It may ask to rescan adapter, click yes. Now you can see the FreeNAS iSCSI disk listed under devices.


11)   So far, we have set up the VMware vSphere (ESXi) server to detect FreeNAS iSCSI disk through its software adapter. Still, the iSCSI disk is not added as storage in the ESXi4 server. To add this iSCSI disk as vSphere storage go to Storage option under configuration (Shown in step -3). Click on Add storage as shown below.


12)   Select Disk/LUN and press Next.  Now FreeNAS iSCSI disk will appear. Select it and click Next. The following message will appear once successfully added.


13)   Give a name for datastore and click Next.

14)   Next screen for formatting, leave the default block size and enable maximum size. Press Next.

15)   Here we go, it’s done. The final display will show the data store details. We successfully added FreeNAS iSCSI disks to VMware vSphere (ESXi) data centre. Click Finish to complete the setup.

16)   Now the FreeNAS iSCSi disk is listed under vSphere datastore where you can work as normal datastore.

Connect FreeNAS iSCSI Disks VMware vSphere 4

I’m sure these steps will be helpful to add FreeNAS or any other iSCSI disks to VMware vSphere (ESXi) server. Don’t forget to take a snapshot of the ESXi virtual machine before and after these steps.

Let me know if you face a problem with these methods. If this guide is useful, do drop me a comment below.

Dinesh is the founder of Sysprobs and written more than 400 articles. Enthusiast in Microsoft and cloud technologies with more than 15 years of IT experience.

9 thoughts on “How to Connect FreeNAS iSCSI Disks to VMware vSphere (ESXi)”

  1. Thanks for your articles on how to get a free NAS up and running within VMWare. Really appreciate it, I’m working on Exchange 2007 clustering FE/BE configuration and then moving on to Exchange 2010 in the same fashion. This is really helpful. I want to send a pingback to you from my site as well, this is really good information.

    • @Jason,
      Thanks for your comment.
      With the same method I managed to install Exchange 2010 on Cluster with FreeNAS. It’s cool, isn’t?
      I love pingbacks.

  2. I also really liked the article. Now I have job to do this weekend.

    I would say thanks Dinesh,

    Renato from Brazil.

  3. Thanks for the article, but got question. As you mentioned in your article “Installed three Windows 2008 R2 operating systems in ESXi4. ( one as domain controller and two for Exchange cluster)”. Nested VM doesn’t allow x64bit OS like 2008 R2. How did you install 2008 R2 inside ESXi4 and inside VMware workstation?

  4. You could even run FreeNAS as VM on the ESXi vSphere Host itself. Give all disk space to the FreeNAS server and provide the disk space back to ESXi using iSCSI 🙂
    This way you need only one machine and can take advantage of ZFS and file system snapshots on the datastore.

  5. Hello,

    The material is really good but I have some issues to finish this works. Currently, we have an FreeNAS and vsphere 4.1. and I create a LUN 2TB on the FreeNAS but I have an error on the step “12) Select Disk/LUN and press Next.” .

    The error is “Error adding a datastore in VMware ESXi 4.1 – Call “HostDatastoreSystem.QueryVmfsDatastoreCreateOptions” for object “ha-datastoresystem” on ESXi failed”.

    How can solve this error?.


Comments are closed.

Pin It on Pinterest