The Economics of Software Defined Storage

I’ve written before about object storage and scale-out software-defined storage. These seem to be ideas whose time has come, but I have also learned that the economics of these solutions need to be examined closely.

If you look to buy high function storage software, with per TB licensing, and premium support, on premium Intel servers with premium support, then my experience is that you have just cornered yourself into old-school economics. I have made this mistake before. Great solution, lousy economics. This is not what Facebook or Google does, by the way.

If you’re going to insist on premium-on-premium then, unless you have very specific drivers for SDS, or extremely large scale, you might be better to go and buy an integrated storage-controller-plus-expansion-trays solution from a storage hardware vendor (and make sure it’s one that doesn’t charge per TB).

With workloads such as analytics and disk-to-disk backups, we are not dealing with transactional systems of record and we should not be applying old-school economics to the solutions. Well managed risk should be in proportion to the critical availability requirements of the data. Which brings me to Open Source.SED

Open Source software has sometimes meant complexity and poorly tested features and bugs that require workarounds but the variety, maturity and general usability of Open Source storage software has been steadily improving, and feature/bug risks can be managed. The pay-off is software at $0 per usable TB instead of US$1,500 or US$2,000 per usable TB (seriously folks, I’m not just making these vendor prices up).

It should be noted that open source software without vendor support is not the same as unsupported. Community support is at the heart of the Open Source movement. There are also some Open Source storage software solutions that offer an option for full support, so you have choice about how far you want to go.

It’s taken us a while to work out that we can and should be doing all of this, rather than always seeking the most elegant solution, or the one that comes most highly recommended by Gartner, or the one that has the largest market share, or the newest thing from our favorite big vendors.

It’s not always easy and a big part of the success is making sure we can contain the costs of the underlying hardware. Documentation and quoting and design are all considerably harder in this world, because you’re going to have to work out a bunch of this for yourself. Most integrators just don’t have the patience or skill to make it happen reliably, but those that do can deliver significant benefits to their customers.

Right now we’re working solutions based on S3 or iSCSI or NFS scale out storage with options for community or full support. Ideal use cases are analytics, backup target storage, migration off AWS S3 to on-premises to save cost, and test/dev environments for those who are deploying to Amazon S3, but I’m sure you can think of others.

Treat me like an Object!

Object Storage that is…

By now most of us have heard of Object Storage and the grand vision that life would be simpler if storage spent less time worrying about block placement on disks and walking up and down directory trees, and simply treated files like objects in a giant bucket, i.e. a more abstracted, higher level way to deal with storage.

May latest blog post is all about how Object Storage differs from traditional block and file, and also contains a bit of a drill down on some of the leading examples in the market today.

Head over to for the full post.

Thank you for your I.T. Support

Back in 2011 I blogged on buying a new car, entitled the anatomy of a purchase. Well, the transmission on the Jag has given out and I am now the proud owner of a Toyota Mark X.

Toyota Mark-X

The anatomy of the purchase was however a little different this time. Over the last 4 years and I found that the official Jaguar service agents (25 Kms away) offered excellent support. 25 Kms is not always a convenient distance however, so I did try using local neighbourhood mechanics for minor things, but quickly realized that they were going to struggle with anything more complicated.

Support became my number one priority

When it came to buying a replacement, the proximity of a fully trained and equipped service agent became my number one priority. There is only one such agency in my neighbourhood, and that is Toyota, so my first decision was that I was going to buy a Toyota.

I.T. Support

Coming from a traditional I.T. vendor background my approach to I.T. support has always been that it should be fully contracted 7 x 24, preferably with a 2 hour response time, for anything that business depended on. But something has changed.

Scale-Out Systems

The support requirements for software haven’t really changed, but hardware is now a different game. Clustered systems, scale-out systems, web-scale systems, including hyper-converged (server/storage) systems will typically quickly re-protect a system after a node failure, thereby removing the need for panic-level hardware support response. Scale-out systems have a real advantage over standalone servers and dual controller storage systems in this respect.

It has taken me some time to get used to not having 7×24 on-site hardware support, but the message from customers is that next-business-day service or next+1 is a satisfactory hardware support model for clustered mission-critical systems.

Nutanix Logo

Nutanix gold level support for example, offers next-business-day on-site service (after failure confirmation) or next+1 if the call is logged after 3pm so, given a potential day or two delay, it is worth asking the question “What happens if a second node fails?”

If the second node failure occurs after the data from the first node has been re-protected, then there will only be the same impact as if one host had failed. You can continue to lose nodes in a Nutanix cluster provided the failures happen after the short re-protection time, and until you run out of physical space to re-protect the VM’s. (Readers familiar with the IBM XIV distributed cache grid architecture will also recognise this approach to rinse-and-repeat re-protection.)

Nutanix CVM failure2

This is discussed in more detail in a Nutanix blog post by Andre Leibovici.

To find out more about options for scale-out infrastructure, try talking to ViFX.

Toyota Support

How well do you know your scale-out storage architectures?

The clustered/scale-out storage world keeps getting more and more interesting and for some they would say more and more confusing.

There are too many to list them all here, but here are block diagrams depicting seven interesting storage or converged hardware architectures. See if you can decipher my diagrams and match the labels by choosing between the three sets of options in the multi-choice poll at the bottom of the page:


D Nutanix
E Nimble
F IBM GPFS Storage Server (GSS)
G VMware Virtual SAN




D Nutanix
E Nimble
F IBM GPFS Storage Server (GSS)
G VMware Virtual SAN


You can read more on VMware’s EVO:RAIL here.

Hypervisor / Storage Convergence

This is simply a re-blogging of an interesting discussion by James Knapp at looking at VMware Virtual SAN. Even more interesting than the blog post however is the whitepaper “How hypervisor convergence is reinventing storage for the pay-as-you-grow era” which ViFX has come up with as a contribution to the debate/discussion around Hypervisor storage.

I would recommend going to the first link for a quick read of what James has to say and then downloading the whitepaper from there for a more detailed view of the technology.



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