Martin “Storagebod” Glassborow suggests two reasons EMC reversed course on virtualizing behind the VMAX: Maintaining margin on controllers and adapting to a flash-filled world. Both are reasonable ideas…

The speed of change in the spinning rust market appears to be slowing, certainly the incessant increase in the size of hard disks is slowing and there means that there might be less pressure to technically refresh the spindles and a decoupling of the disk from the controller makes sense. EMC can protect their regular upgrade revenues at the controller level and forgo some of the spinning rust revenues. They can more than make up for this out of maintenance revenues on the software.

But I wonder if there is a more pressing technological reason and trend that means that it is a good time to do this; that is the rapid progress of flash into the data-centre and how EMC can work to increase the acceleration of adoption. It is conceivable that EMC could be looking shipping all-flash arrays which allow a customer to continue to enjoy their existing array infrastructure and realise the investment that they have made. It is also conceivable that EMC could use a VMAX like appliance to integrate their flash-in-server more simply with a third party infrastructure.

© Stephen Foskett for Gestalt IT, 2012. | Virtually Pragmatic?
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© Stephen Foskett for Gestalt IT, 2011. | Thin Provisioning: Playing the Telephone Game
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The traditional datacenter is comprised of servers, network, and storage. We have all seen major changes in server architectures (including newer processors, new instruction sets, faster RAM, PCIe, and Blade architecture) and storage architecture (SAN/NAS functionality, SSDs/EFDs, caching improvements, replication, and storage tiering). These improvements have shown major benefits to the users of these systems and have kept capital investments in IT moving along as IT departments have been able to improve stability and performance due to them.

However, there has been a lack in mainstream improvement in network performance as well as a newcomer to the datacenter, virtualization, that stand to make a major change in how datacenters operate in the very near future.

The last major datacenter network change involved the adoption of 1Gbps networking from 10/100. I am sure there are some network guys that would love to debate this to no end (feel free to talk amongst yourselves, then). Server hardware began to include 1Gb NICs onboard and the switch manufacturers dropped the price of the 1Gb switching. At that point, almost anyone with some money and a datacenter could immediately realize the benefit of increasing the network performance 10-fold.

Since then, though, the network has been lacking in performance gains. Technologies and techniques, such as Infiniband, Port Channels, and NIC teaming all assist in boosting the performance in some fashion, but they are not commodity like being able to plug in an existing 1Gb NIC into a 1Gb switchport and everything work faster. However, fairly recently, the introduction of 10Gb networking has emerged. The same pattern will follow as with the adoption of 1Gb networking… NICs onboard, switching costs drop, adoption ensues. Suddenly, 10Gb networking will penetrate the market.

The new player to the datacenter is virtualization. Now, it is common to think of virtualization as server virtualization (aka – VMware vSphere, Microsoft Hyper-V, Citrix XenServer, etc…). However, virtualization is really just a layer of abstraction. In some situations, like server virtualization, this happens by the use of a hypervisor to abstract the hardware from the software layer. However, the same concept of virtualization as abstraction can be applied to other areas of the datacenter.

So, what can be abstracted and virtualized? Well… almost anything that is historically tied to being hardware specific. Categories like I/O Virtualization (Companies: Aprius and Xsigo), Storage Virtualization (Companies: Isilon/EMC, NetApp, Avere), and Network Virtualization (Cisco, Open vSwitch, VMware, and Citrix). Suddenly, what used to be specific to hardware has been lifted into a realm where it is not necessarily the case. Sure, PCIe cards are still tied to hardware for access… however, it is not necessarily on the physical server itself.

Higher bandwidth networking in the datacenter means that more and more data can be put on a network at any given time without impacting other operations. So, I/O functions like Fibre Channel storage and PCIe I/O are suddenly able to exist on the datacenter Ethernet network. Virtualization is becoming the mechanism to allow for the convergence of non-traditional data on the Ethernet network.

The addition of virtualization and high bandwidth networks is leading to a new shift in the functions of the datacenter components. Now, we are seeing more and more intelligence being placed on the service level and less and less functionality in the core datacenter components. Products are coming to market that remove functionality from the datacenter components and perform functions themselves. SAN caches are being placed in the data path that interrupt the flow to the primary SAN in order to increase performance. PCI cards are being removed from hosts and shared across multiple hosts, over Ethernet. Network decisions (VLANs, for example) are now being deployed to virtual servers, like ESXi and Hyper-V… virtual switches are even extending across multiple hosts (vDS, in vSphere environments). Some very powerful networking switches are being virtualized and deployed in virtual server environments (see Cisco Nexus 1000v and Open vSwitch) and away from the formerly closed hardware environments.

The change in the functions of core datacenter components is really a mixed bag. Partially a case of “what a great idea!” and “just because you can does not mean you should”. I feel that the virtualization of server hardware is leading to some pretty cool things… mostly, a time to re-question how a service is provided. Vendors are re-thinking about needing an expansion being a hardware device or a service being provided over the network. This leads to server hardware becoming smaller, more dense, and more cost efficient (lower cooling and power needs with high performance).

The Network virtualization is very much a middle ground for me. Removing network intelligence from network devices is not a good idea. The network devices are designed and built for efficiency and logic as to how to process the data. Removing that logic and placing it elsewhere is a step in the wrong direction. However, being able to extend network logic into areas once unavailable becomes a major benefit to everyone. Projects/products like Open vSwitch are really pushing the adoption of virtual network switches into the forefront of the server virtualization world as it provides major network functionality at the virtual switch level that puts the “devices” at the same level as traditional hardware switches.

Storage virtualization is another middle ground area for me. Abstracting the data on the storage device and allowing the device to logically place the data on tiers is amazing technology. This allows for higher performance on most frequently used data, block and file level access to data on the same storage groups, file access via metadata, and so much more. The issue becomes with the ever-so-precious data path. Storage admins are very hesitant to place a device in the middle of the storage path. Suddenly, there is another variable that can impact the quality and consistency of the Corporate data. So, while a product like Avere is so cool, it is inline and people are weary of that.

All of the virtualized components listed above require some level of Ethernet bandwidth for them to work properly. By increasing the bandwidth available on the network, these new technologies are making their way into the datacenters. We just need to ask ourselves “just because we can, does that mean we should?” 

© Bill for Gestalt IT, 2010. | Virtualization and High Bandwidth Datacenter–How the Datacenter Landscape Is Changing
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‘storage access is further decoupled from storage physicality’

And this really is nothing especially new; decoupling the storage access from storage physicality has been going on for some time. Servers are getting further and further away from their physical disk. We have been adding abstraction layers to storage access for some time, the big question is whether we need another abstraction layer?

Actually I think that the additional layer is useful; the ability to present ‘real LUNS’ from ‘storage arrays’ as a single ‘plexed LUN’ and keeping these LUNs in-sync might actually be useful in a number of use-cases. I can see it simplifying and transforming DR for example; I can see it making migration a lot easier and I can see EMC heavily leveraging their VMWare investments. I’ve said it before and I’ll say it again; ever since EMC spun VMWare off, they have acted more in concert than when VMWare were wholly owned.

Is it useful enough to warrant EMC’s claim to have invented a new class of storage device?

I think I’ll let the vendor bloggers rip themselves to shreds over that.

I also think it is interesting that they have at long last decided to pretty whole-heartedly support third party arrays; if anything, this makes it an interesting announcement for EMC. Will they sell any? Well, it’s going to be an uncomfortable experience for your run-of-the-mill account manager when faced with a Storage Manager who says ‘Well you’ve just re-invented SVC/USP-V etc…you told me that they were rubbish, so why is yours any good?’

I think the heavy-hitters in EMC are going to be very busy supporting their account-teams.

© Martin for Gestalt IT, 2010. | V(per)PLEXed?
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The response is not really to do with virtualisation at all; it is all about aligning IT and Business. He talks about an all too familiar case where storage decisions are made locally by the Business Units and the procurement strategy does not take account of the long-term health of the group; ongoing OpEx costs are not born by individual business units and become the problem of the IT department. The concept and value of shared infrastructure was not really understood by the Business.

But I suspect that these very same Business Units will be happy to use Cloud-based services, Infrastructure as a Service etc, concepts which are built on multi-tenanted shared external infrastructure. Why? Because they can deploy rapidly and flexibly; they don’t need to engage the slow and cumbersome IT department and they feel that they are masters of their own destiny.

Storage virtualisation won’t bring these Business Units back but storage virtualisation may enable IT to put together a flexible and responsive service catalogue. CIOs need to engage with their customers and understand what they want but they need the support of vendors to clearly demonstrate cost to their customers and to their boards.

The service must be something that the customer wants, customers do not understand why it takes weeks to provision servers, storage and networks. They can go down to PC World and the likes and pick things off the shelf *NOW*.

The more savvy customer knows that they can enter a credit card number into a cloud provider and can provision dozens of servers much quicker than the IT department can and what’s more, they can turn them off again equally quickly and not be stuck with kit that they do not need and do not want.

Customers want dynamic, flexible infrastructures which can rapidly respond to their needs; Corporate IT departments along with their vendors have been pretty poor at providing these. Virtualisation and abstracted infrastructures are enabling technologies but Hu’s right in that people and processes are key…

As for external storage virtualisation devices, I still wonder if they are the future? They are not necessary to provide the service and if I was building a green-field data centre with no legacy to deal with, I am not sure I would deploy them.

Infrastructure provision is at an interesting inflection point; if you don’t understand this and your customers do, you have got a problem.

© Martin for Gestalt IT, 2009. | Flexible Thinking
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I think in many ways his idea gets to the core about what might have gone wrong with the storage industry; we are paying too much for the commodity bit of the storage i.e the spinning stuff!!

But is what Hu is talking about truly virtualisation? Arguably not!  What HDS do and what IBM do with SVC is more loosely couple the array controller with the disk at the back-end. USP and SVC are simply array controllers. Storage virtualisation actually is not really that clever, the USP and SVC may have some fantastic code in but they are “simply” array controllers. And yes they have to deal with the vagaries of FC implementation across many different back-end disks and EMC would probably argue ‘more fool them’.

So perhaps if instead of selling Virtualisation; IBM and HDS simply sold array controllers and said, ‘You can buy your disk from us, EMC or whoever is giving the best deal today’ and didn’t make it out to be some mystical and magical thing; they might get more acceptance.

It actually changes the nature of conversation somewhat, end-users could then go back to EMC et al and ask the question, ‘What makes your back-end disk so special? Why can’t I just buy the directors and put what ever disk I like behind it?’.

I think the discussion becomes a lot less philosophical and a lot more pragmatic if this approach is taken. I know EMC have answers as to why their back-end disk is special but perhaps you should ask the question also. We can get down to talking about each storage array’s USP…no pun intended!

© Martin for Gestalt IT, 2009. | Storage Virtualisation and Commoditisation
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