As we are delving into Microsoft’s free iSCSI Target software there are a number of key resources available to us for the product.
The download is available here:
There are a number of different resources available to us:
- TechNet: Microsoft iSCSI Software Target 3.3 Implementation Notes
- TechNet: Support Policies for Microsoft iSCSI Software Target 3.3 on Windows Server 2008 R2
- TechNet: Microsoft iSCSI Software Target 3.3 Known Issues and Updates
- Microsoft KB2535811: Supported and tested Microsoft iSCSI Software Target 3.3 limits
- Note that this KB looks to be out of date as the TechNet Scalability Limits page has what looks to be a newer version of the KB content.
The following link is the the Microsoft iSCSI Software Target 3.3 Product Help:
Under Product Help we find a list of operating systems that it can be installed on. Unfortunately it looks as though Windows Storage Server 2008 R2 Essentials is not one of them.
iSCSI Target and Adapter Teaming
One of the notes in the KB and Scalability pages talk about network adapter teaming _not_ being supported.
From that article we find:
Use Microsoft MultiPath IO (MPIO) to manage multiple paths to iSCSI storage. Microsoft does not support teaming on network adapters that are used to connect to iSCSI-based storage devices. This is because the teaming software that is used in these types of configurations is not owned by Microsoft, and it is considered to be a non-Microsoft product. If you have an issue with network adapter teaming, contact your network adapter vendor for support. If you have contacted Microsoft Support, and they determine that teaming is the source of your problem, you might be required to remove the teaming from the configuration and/or contact the provider of the teaming software.
So, we see that the reason given here has to do with the teaming being provided by third parties.
So, off to Intel we go to see what they state:
- Intel Server Products Support: Is Adapter Teaming supported on any system which carries iSCSI traffic?
The answer is “No”. Unequivocally “No”. From the Intel support page:
Adapter Teaming using Intel's ANS is not supported for those ports transferring iSCSI traffic. This is due to limitations of the third-party iSCSI target/initiator software.
For load balancing and failover support in Microsoft Windows* operating systems, you can use Microsoft's* MPIO (MultiPath I/O). Check the Microsoft Initiator User Guide on how to setup MPIO.
If you are planning to use Microsoft MPIO on an Intel® Storage System, please ensure that your firmware supports multi path I/O.
Now, so far our test iSCSI Target box (previous post) has been running fine with the three NICs teamed in Load Balancing Mode. However, since we are running in an unsupported configuration we will look to see about how to configure MPIO on that box.
Once we have our iSCSI Target set up we need to connect to it!
The iSCSI Initiator Guide for Windows 7 and Windows Server 2008 R2 can be downloaded here:
When working with Server Core R2 installations the iSCSI Initiator GUI can be started by the following command:
- iscsicpl.exe [Enter]
Server Core iSCSI Initiator GUI
Here is a blog post on enabling this functionality in Server Core 2008 RTM:
- Windows Storage Management Blog: How to add the iSCSI Initiator User Interface to Windows Server 2008 Server Core edition
iSCSI MPIO Configurations
One aspect that we will need to look into will be how to enable and configure multiple I/O paths to our iSCSI located storage if we were looking to use that storage for clustered VM VHD storage.
- Windows Storage Server Blog: Shared storage for Windows Failover Cluster with MPIO
- Off Campus Blog: Configuring iSCSI MPIO on Windows Server 2008 R2 (full)
For now we will be sticking with our DAS configurations, but there may be a need to look at iSCSI MPIO as an failover cluster storage alternate especially if this type of configuration brings the cost of a 2 node cluster down.
As we can see, there is a _lot_ of reading that needs to be done in order to understand the ins and outs of using Microsoft’s iSCSI Software Target. Plus, we need to check into our backup box’s configuration to figure out how to work iSCSI with multiple NIC ports.
Microsoft Small Business Specialists
Co-Author: SBS 2008 Blueprint Book