So at VMworld Barcelona we announced Virtual SAN 6.5, also known as VSAN 6.5 So what are the main cool things about VSAN 6.5. First of all there is iSCSI, then we have 2 Node direct connect, there is also 512e drive support and more. So lets jump into this.

So what is VSAN iSCSI?

The VSAN iSCSI feature basically gives VSAN the ability to present iSCSI LUNS to external hosts. Now each of these LUNs can have their own performance and availability requirements because each of these LUNs will use Storage Policies. That’s because these LUN’s are actually objects from a VSAN point of view.  It is easy to set up using the vSphere Web Client. So if you have free space in your VSAN 6.5 cluster then you can utilize this space outside of your cluster. Please note that you cannot present these iSCSI LUNs to your ESXi hosts

Some commands you can use for iSCSI investigation

esxcli vsan iscsi target list

esxcli vsan iscsi target get -a

esxcli vsan iscsi target lun list -t 

esxcli vsan iscsi namespace get

2 Node direct connect

Usually we need switches to connect 2 hosts together, however in VSAN 6.5 we can use a network cable and connect these 2 hosts directly together and you will therefore gain optimal performance. So if you have 10GbE NICs then you will get 10GbE speeds between these hosts . For customers that have ROBO sites there are huge benefits to be had here.

With 2 hosts what will happen from a witness point of view? A witness node will need to be created back at the Central Office. All ROBO sites are managed by the vCenter back at that Central Office. The witness is handled by the virtual appliance which is again sitting back at the Central Office. A witness network is required and a VSAN network is also required. So when we break up these networks it means no more static routes. So we are now decoupling witness traffic from data traffic.

What steps are involved in the setup? Some commands that need to be used in setting this up are the following:

esxcli vsan network list to check your Traffic Type (it will usually say vsan when you check the Traffic Type section).

To set the traffic type to witness use the following command :

esxcli vsan network ip set -i vmk<#> -T=witness

You can change the traffic type back again if necessary by using -T=vsan

512e drive support

The goal here is that VSAN will be able to use larger capacity disk drives in the future. So right now we do not support 4k drives however we do support 512e (emulation). Keep in mind, that the 4Kn support for release vSphere 2016 is relevant only to HDDs and thereby only hybrid VSAN arrays. All SSDs are basically 512e (4Kn internal) and enterprise quality SSDs should do 4 KB RMW using non-volatile memory so overhead should be negligible.


Very briefly, you can now use a standard VSAN license to deploy an All Flash VSAN cluster. However you will not be able to utilize dedupe and compression along with RAID5/6 unless you use an Advanced license version.

PowerCLI for VSAN

Using PowerCLI customers will be able to automate VSAN tasks.


So in summary the new features in VSAN 6.5 are pretty cool, especially iSCSI and 2 node direct connect. Stay tuned for new VSAN troubleshooting materials coming soon. 🙂