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mprazeres183 Hot Shot

vSAN 6.6

Posted by mprazeres183 Nov 23, 2017

I have been working with ESX since a long time now, if I try to remember back to the beginning of my journey in to the virtualization world, I didn’t really get along with it. At least not at the beginning. After ESXi 4.1 came out I took part on a boot camp and OMG that really changed on how exited I became with VMWare and ESXi as the Hypervisor I selected to work with. In the past years there was a lot of innovation and frustration. One of the frustrations might have been the part that VMWare took the decision to remove vSphere Client and go to a full Web-Client function, that at the same time is an innovation and now to be honest, I couldn’t work without it anymore! I feel lost when I use the Thick Client! As there are so much new stuff you can find on the FLASH Web version. But what really triggered me in to writing my first blog, is about the very exiting vSAN feature along with ESXi 6.5 that we are using for the company I was hired to get the vSAN globally up and running.


So, I come from the basic storage array world, where you work with SAN storage and you have to zone everything to the ESXi Host and then be sure to have everything also worked out with your backup software, otherwise backup will fail, and this and that… Well I think for all of you who worked on ESXi with Classic Storage array know about the thrill?


But what if there is something, easy, very scalable, cheap and just fun to work with? Would you consider it?


To be fair, I was skeptical at the beginning… At the beginning meaning like 6 months ago, when I can to this gig, I told them to buy 2 XTREM-IO from EMC, it will be easier, cheaper and better. I was so mistaken!


So let’s come to the conclusion or to what I’ve build:


The Customer was very specific on what they wanted:
The wanted their DMZ on a Storage system who’s management was easy, fast, scalable and (well cheap or expensive was not really part of the deal) so let’s say and futuristic. So what is more future than converged storage? Correct! Hyper-Converged Infrastructure on the basis of vSAN that was what I decided to get along with. After a LAB and everything run well for 3 Months, we started with the documentation (That was a long one) me coming from a big company with a lot of documentation skills I knew on how to get that drafted, so that the management would take that offer.


So as I said, they loved the idea and they booked me till end of 2020 to get the systems up and running globally, and this is the whole story of it on how vSAN and why vSAN.


Why vSAN?
I use Chan as an inspiration for it. (Just changed that it matches also me)


I’ve been a traditional SAN storage guy out in the field where I’ve worked hands on with key enterprise SAN storage tech from NetApp, EMC ….etc. for a long time. I’ve worked with these in all aspects, starting from design, deployment and ongoing support. They are all very good I still like their tech and they sure do have a definite place in the Datacentre still. But they are a nightmare to size accurately, nightmare to design and implement and even a bigger nightmare to support when in production use, and that’s from a techie’s perspective. From a business / commercials perspective, not only are they expensive to buy upfront and maintain, but they typically come with an inevitable vendor lock-in that keeps you on the hook for 2-5 years where you have to buy substantially overpriced components for simple capacity upgrades. It is also very expensive to support (support costs are typically 17%-30% of the cost of SAN) and can be even more expensive when the originally bought support period runs out because the SAN vendor would typically make the support renewal cost more expensive than buying a new SAN, forcing you down to buy another. I suppose this is how the storage industry has always managed to pay for itself to keep innovating & survive but many customers and even startup SAN vendors are waking up to this trick and have now started to look at alternative offerings with a different commercial setup.

As an experienced storage guy, I can tell you first hand that the value of enterprise SAN storage is NOT really in the tin (disk drives or the blue / orange lights) but in fact in the software that manage those tin elements. Legacy storage vendors make you pay for that intelligence once, when you buy the SAN with its typical controllers (brains) where this software live and then every time you add additional disk shelves through guaranteed over priced shelf upgrades subsequently (ever heard your sales person tell you to estimate  all your storage needs for the next 5 years and buy it all up front with your SAN as its cheaper that way??). SAN vendors have been able to overcharge for subsequent shelf upgrades simply because they have managed to get the disk drive manufacturers to inject some special code (proprietary drivers) on to the disk firmware without which their SAN will not recognise the disks in its system so the customer cannot just go buy a similar disk elsewhere, even if that was the same disk made by the same end manufacturer (vendor lock-in). This overpricing is how the SAN vendor gets the customer to pay for their software intelligence again, every time you add additional capacity. I mean think about it, you’ve already paid for the damn SAN and its software IP when buying the SAN in the first place, so why pay for it again through paying over the odds when adding some more shelves to it (which after all, only contain disk drives with no intelligence) to expand its capacity?

To make it even more worse, the SAN vendor then comes up with a brand new version of the SAN in few years time (typically in the form of new software that cannot run on the current hardware you have, or a brand new SAN hardware platform all together). And your current SAN SW has now been made end of life therefore is not in support anymore (even though its working fine still). Now, you are stuck with an artificially created scenario (by the SAN vendor of course and forced upon you) where you cannot carry on running your existing version without paying a hefty support renewal fee (often artificially bloated by the vendor to be more expensive than a new HW SAN) nor can you simply  upgrade the software on the current hardware platform as the new SW is no longer supported by the vendor on your existing HW platform anymore. And transferring the software license you’ve already bought over to a new set of hardware (new SAN controllers) is strictly NOT allowed either.. (A carefully orchestrated and a very convenient scenario isn’t it for the SAN vendor?). Enters the phrase “SAN upgrade” which is a disruptive, labourous and worst of all an un-necessary expense where you are now indirectly forced by the vendor to pay again for the same software intelligence that you’ve already supposedly paid for, on a different set of hardware (new SAN). This is a really good business model for the SAN vendor and there’s also a whole eco system of organisations that benefit massively from this recurring (arguably never ending) procurement cycle, at the expense of the customer.

I see VMware VSAN as one of the biggest answers to this, for the vSphere shared storage use cases… With VMware VSAN, you have the freedom to choose your hardware including cheaper commodity hardware where you only pay the true cost of the disk drive based on its capacity without having to also pay a surcharge for the software intelligence every time you add a disk drive to your SAN. With VSAN which is licensed per CPU socket instead of per capacity unit (MB/GB/TB) so you pay for the software intelligence once irrespective of the actual capacity, during the initial procurement and that’s it. For every scale up requirement (adding capacity), you can simply just buy the disk drives at their true cost and add it to existing nodes. If you need to scale out (add more nodes), you then pay for the CPU sockets on the additional node(s). That to me sounds a whole lot fairer than the traditional SAN vendors model of charging for software upfront and then charging for it again indirectly during every capacity upgrade & SAN upgrade. Unlike traditional SAN vendors, every time a new version of the (VSAN) software comes out, you upgrade your ESXi version which is totally free of charge (if you have on going support) so you never have to pay for the software intelligence again (even when the ESXi host hardware replacement is required in future, you can reuse the VSAN licensing on the new HW nodes which is something traditional SAN vendors don’t let you do)

Typically, due to all these reasons, a legacy HW SAN would cost around $7 – $10 per GB whereas with VSAN, it tends to be around $1 – $2 mark, based on the data I’ve seen.

A simple example of upfront cost comparison is below. Note that show only shows the difference in upfront cost (CAPEX) and doesn’t take in to account ongoing cost differences which makes it even more appealing, due to the reasons explained above.

How vSAN:


  • · Its flexible

o VSAN being a software defined storage solution gives the customer the much needed flexibility where you are no longer tied in to a particular SAN vendor.

o You no longer have to buy expensive EMC or NetApp disk shelves either as you can go procure commodity hardware to design your DC environment as you see fit

  • · It’s a technically better storage solution for vSphere


o Since VSAN drivers are built in to the ESXi kernel itself (Hypervisor), its directly in the IO path of VM’s which gives it superior performance with sub millisecond latency

o Also tightly integration with other beloved vSphere features such as VMotion, HA, DRS and SVMotion as well as other VMware Software Defined Datacenter products such as vRealize Automation and vSphere replication.

  • · Simple and efficient to manage


o Simple setup (few clicks) and policy based management, all defined within the same single pane of glass used for vSphere management

o No need for expensive storage admins to manage and maintain a complex 3rd party array

o If you know vSphere, you pretty much know VSAN already

o No need to manage “LUNs” anymore – If you are a storage admin, you know what a nightmare this is, including the overhead of the management of the HW fabric too.

  • · Large scale out capability

o Support up to 64 nodes currently (64 node limitation is NOT from VSAN but from underlying vSphere. This will go up with future versions of vSphere)

o 6,400 VMs / 7M iops / 8.8 petabytes

  • · High availability

o Provide 99.999 for availability by default

o No single point of failure due to its distributed architecture

o Scaling out (adding nodes) or scaling up (adding disks) does not require downtime ever again.


VMware vSAN to me is this:
I don’t like the solution, I really love it! The idea behind and how it was worked out is very professional and the way you can add value to your infrastructure in just some configuration changes and work with what you have its fabulous.


I’m not a partner of VMWare nor do I sell their products, but I work with them and I use their technology going forward I will ask myself and future customers why not using the power of the Converged Storage of VMware before going to a solution that will hold you for years, cost you a ton of money and not be scalable (fast) as this solution here!


So if you need any advice, feel free to contact me, also read all my Forum posts.

Thanks a lot,


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