VSAN 6.0 includes a large number of new enhancements and capabilities that I am sure many of you are excited to try out in your lab. One of the challenges with running VSAN in a home lab environment (non-Nested ESXi) is trying to find a platform that is both functional and cost effective. Some of the most popular platforms that I have seen customers use for running VSAN in their home labs are the Intel NUC and the Apple Mac Mini. Putting aside the memory constraints in these platforms, the number of internal disk slots for a disk drive is usually limited to two. This would give you just enough to meet the minimal requirement for VSAN by having at least a single SSD and MD.
If you wanted to scale up and add additional drives for either capacity purposes or testing out a new configurations, you are pretty much out of luck, right? Well, not necessary. During the development of VSAN 6.0, I came across a cool little nugget from one of the VSAN Engineers where USB-based disks could be claimed by VSAN which could be quite helpful for testing in a lab environment, especially using the hardware platforms that I mentioned earlier.
For a VSAN home lab, using cheap consumer USB-based disks which you can purchase several TB's for less than a hundred dollars or so and along with USB 3.0 connectivity is a pretty cost effective way to enhance hardware platforms like the Apple Mac Mini and Intel NUCs.
Disclaimer: This is not officially supported by VMware and should not be used in Production or evaluation of VSAN, especially when it comes to performance or expected behavior as this is now how the product works. Please use supported hardware found on the VMware VSAN HCL for official testing or evaluations.
Below are the instructions on how to enable USB-based disks to be claimable by VSAN.
Step 1 - Disable the USB Arbitrator service so that USB devices can been seen by the ESXi host by running the following two commands in the ESXi Shell:
chkconfig usbarbitrator off
Step 2 - Enable the following ESXi Advanced Setting (/VSAN/AllowUsbDisks) to allow USB disks to be claimed by VSAN by running the following command in the ESXi Shell:
esxcli system settings advanced set -o /VSAN/AllowUsbDisks -i 1
Step 3 - Connect your USB-based disks to your ESXi host (this can actually be done prior) and you can verify that they are seen by running the following command in the ESXi Shell:
Step 4 - If you are bootstrapping vCenter Server onto the VSAN Datastore, then you can create a VSAN Cluster by running "esxcli vsan cluster new" and then contribute the storage by adding the SSD device and the respective USB-based disks using the information from the previous step in the ESXi Shell:
esxcli vsan storage add -s t10.ATA_____Corsair_Force_GT________________________12136500000013420576 -d mpx.vmhba32:C0:T0:L0 -d mpx.vmhba33:C0:T0:L0 -d mpx.vmhba34:C0:T0:L0 -d mpx.vmhba40:C0:T0:L0
If we take a look a the VSAN configurations in the vSphere Web Client, we can see that we now have 4 USB-based disks contributing storage to the VSAN Disk Group. In this particular configuration, I was using my Mac Mini which has 4 x USB 3.0 devices that are connected and providing the "MD" disks and one of the internal drives that has an SSD. Ideally, you would probably want to boot ESXi from a USB device and then claim one of the internal drives along with 3 other USB devices for the most optimal configuration.
As a bonus, there is one other nugget that I discovered while testing out the USB-based disks for VSAN 6.0 which is another hidden option to support iSCSI based disks with VSAN. You will need to enable the option called /VSAN/AllowISCSIDisks using the same method as enabling USB-based disk option. This is not something I have personally tested, so YMMV but I suspect it will allow VSAN to claim an iSCSI device that has been connected to an ESXi host and allow it to contribute to a VSAN Disk Group as another way of providing additional capacity to VSAN with platforms that have restricted number of disk slots. Remember, neither of these solutions should be used beyond home labs and they are not officially supported by VMware, so do not bother trying to do anything fancy or running performance tests, you are just going to let your self down and not see the full potential of VSAN 🙂