VSAN for Service Providers

Since VMworld in San Francisco, VMware have been on a tear backing up all the VSAN related announcements at the show by starting to push a stronger message around the improvements in the latest VSAN release. Cormac Hogan and Rawlinson Rivera have published articles while Duncan Epping has also released a number of articles around VSAN since VMworld including this one on VSAN Licensing and what’s included as part of the different Enterprise Packages…There has also been an official post on the vCloud Team Blog on use cases for VSAN Storage Policies in a vCloud Director environment.

Last year I wrote a couple of posts around the time VSAN pricing was being released and also on the specifics of the vCloud Air Network program bundles that allow VSAN to be consumed via the VSPP. At the time there was no All Flash Array option and the pricing through the VSPP was certainly competitive when you compared it to a per socket price.

As a platform, VSAN is maturing as an option for hyper converged deployments and VMware Service Providers are starting to deploy it not only for their Management Clusters, but also main compute and resource clusters. The wording and messaging from VMware has shifted significantly from the first 5.5 VSAN release where they mainly talked about Test/Dev and VDI workloads to now talk about mission critical workloads with 6.x.

While doing research into our new Management Clusters that will use VSAN on top of the new Dell FX2 PowerEdge Converged Platform I was looking into the costs on the vCAN and how it stacks up next to per socket pricing…Shown below are the different Product Bundles included in the vCAN Program…each one contains a different combination of VMware Products which you get access to depending on the bundle of choice (details here).
While I can’t exactly disclose what level we get at Zettagrid (or other providers for that matter) due to the commercial nature of the programs its safe to assume that service providers at scale can drill that US $1 per point price point down by up to 50%…while some could actually pay more.

When you start to look at the cost of running a storage platform for IaaS you start to get an appreciation for the cost per month on the vCAN program that running VSAN offers. At a small to medium scale VSAN via the vCAN Program stacks up…mainly because the program is structured to make the Points Per Month value cheaper the more volume you transact against the program. So an SP consuming large amounts of vRAM will have a lower entry point for VSAN.

Looking at the larger picture, below is an an example software (only) cost of 10 Hosts (64GB RAM) with 100TB of Storage with an expected utilization of 80% assuming 2 hosts are reserved for HA.

VSAN 80TB Allocated vRAM 410GB (205GB Reserved) Per Month
 $6,400 $1,433  $ 7,833

If we scale that to 20 hosts with 128GB and 200TB of Storage with an expected utilization of 80% assuming 4 hosts are reserved for HA.

VSAN 160TB Allocated vRAM 1.6TB (820GB Reserved) Per Month
 $ 12,800 $5,734  $ 18,534.40

You start to see that the cost per month starts to get somewhat questionable when comparing OpEx vs CapEx costs of a traditional SAN purchase outside of the vCAN Program. As an example you should be able to source a traditional SAN under finance with roughly the same usable storage as whats in the second example for about US $4000-6000 per month on a finance plan over 36 months.

Personally I believe the cost per allocated GB is a little on the high side at scale and it could start to become cost prohibitive for Service Providers when comparing to traditional storage pricing models or even some of the latest pricing for newer scale out platforms on the market…and that’s not even thinking about the additional cost of the AFA Add-On.

So, for me VMware need to look at slightly tweaking the vCAN cost model for VSAN to either allow some form of tiering (ie 0-500GB .08, 500-1000GB .05, 1TB-5TB .02 and so on) and/or change over the metering from allocated GB to consumed GB which allows Service Providers to take advantage of over provisioning and only pay for whats actually being consumed in the VSAN Cluster.

If VMware can push those changes through it will make VSAN even more attractive to vCloud Air Network Partners and have VSAN move from mainly Management Cluster consideration to full blown production IaaS use.

References:

http://www.yellow-bricks.com/2015/09/14/virtual-san-licensing-packaging/
http://www.yellow-bricks.com/2015/08/31/what-is-new-for-virtual-san-6-1/
http://www.virten.net/2014/03/vmware-vsan-license-calculator/
https://blogs.vmware.com/vcat/2015/09/vcloud-director-and-virtual-san-sample-use-case.html

3 comments

  • I have had a discussion of sorts with VMware regarding this, my current place of employment was embarking on a private cloud project to provide cloud hosting to our managed services clients. Was told my assumptions were not accurate and provided their own estimates. Would love to discuss in more detail on a less public platform to seek a 2nd opinion.

  • Its very interesting to see another SP come to the same conclusion, we recently had some costing done around this vs traditional SAN implementation vs EMC Scale IO and at no point was it cheaper to do a software based solution. I suspect this may be due to sales reps still getting better commission on hardware sales.

  • Same conclusion here from our end, it doesn’t scale as it should, their justification will be VM aware storage over traditional array however.

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