VMware Cloud on AWS vSAN

Single Host vSAN

VMware recently unveiled a new Single Host VMware Cloud on AWS SDDC.  This new SDDC has been engineered to enable customers to use the VMC Service for up to 30 days at a reduced rate before making any long-term commitments.  At the end of the 30 days, the SDDC will be automatically deleted.  There is currently no way to extend beyond 30 days.  With the launch of this new capability using vSAN as the backing storage, it begs the question…

Can vSAN make an object highly available with a single vSphere host?


The short answer is that it cannot.  vSAN requires at least three hosts to make any object highly available.  In this instance, VMware customers have spoken, and they’re primarily interested in getting hands-on with the VMC service and are willing to accept the risk of potential loss to experience the service first hand and get a proof of value.  To that end, when a Single Host SDDC is created, it contains the same software and configuration that customers will find in a production SDDC’s.


While running on a Single Host SDDC, all VMs and VMDKs stored within vSAN are assigned to a VM Storage Policy with a Failures to Tolerate value set to “No data redundancy”.  Customers can still configure custom Storage Policies, particularly the advanced policy rules such as QoS.  Of course with only a single host and two disk groups, there is a limit to how much these settings will impact performance. Either way the full management experience to include policy configuration is available.

What if I like it?


If you find the VMware Cloud on AWS service suits your needs and would like to keep the instance past 30 days, upgrade to a production 3-Node SDDC with a single click in the VMC web console.  The online non-disruptive upgrade takes advantage of vSAN’s HCI roots to add additional hosts quickly. Finally, a one-time SPBM policy transition changes the VM Storage Policy assignment for all VM’s to the “1 Failure – Raid-1” Failure to Tolerate policy setting. This is currently the only time VMC will “manage” the customer workload VM Storage Policies.

Single Node vSAN is not something VMware currently supports On-premises. In this instance, where we have slightly different requirements, Single Host vSAN has enabled customers to experience the VMC Service at a fraction of the cost.  While the in-place non-disruptive upgrades enable customers considering the VMware Cloud on AWS service, to use Single Host instances as a fail-fast proof of value vehicle, trusting that any successful initiatives can easily transition into full production. To learn more about Single Host SDDC’s as well as the other exciting features announced yesterday be sure to check out our summary post.



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