VCE Vblock to be showcased at the Gartner Data Center Summit

This week I'll be at the Gartner Data Center Summit with VCE at the Park Plaza, Westminster in London, 27-28 November with VCE being a Silver Sponsor of the event.

As usual the VCE stand will be bustling with activity, as we will be featuring the Vblock™ System, exciting and engaging demos and plenty of opportunities to win great prizes.

                        Data Protection
                        Management & Orchestration
                        VDI/Desktop Virtualization
                        And much more...

Those that will wear their VCE “BACK OFF” gear, have the opportunity to potentially be spotted on the show floor and win a prize on the spot. The prize patrol will be out and about looking for your most creative display of “BACK OFF” gear.

If you've not registered for the event, you can do so here:

Look forward to seeing you there!

SplitRXMode – Taking VMware Multicasting to the Next Level

With every new version of vSphere, you’re almost guaranteed an abundance of new features aimed at not only improving previous functionality but also making a VM admin’s life easier. Occasionally though, amongst the copious list of new options there’s always the odd feature which gets overlooked, forgotten or quite simply ignored. One such feature is the SplitRXmode that to my surprise few people knew of when I recommended it for a customer this week. So what better subject to next evangelize and blog about?

Before discussing SplitRXmode, a quick recap on some networking basics and how packet forwarding is done on an IP network.

First there’s the method most folks are familiar with which is Unicast. Unicast transmission sends messages to a single unique network destination identified by a unique IP address, which enables a straightforward onetoone packet delivery. The Broadcast method on the other hand transmits a packet to every device on the network that is within the broadcast domain.

The Unicast method is not suitable for information that needs to be simultaneously sent to multiple recipients

Finally there’s the multicasting method where packet delivery is sent to a group of destinations denoted by a multicast IP address. Multicasting is typically used in applications that have a requirement for simultaneously sending information to multiple destinations such as distance learning, financial stock exchanges, video conferencing and digital video libraries. Multicast sends only one copy of the information along the network, whereby any duplication is at a point close to the recipients, consequently minimizing network bandwidth requirements.

The Multicast method sends only one copy minimizing bandwidth requirements

For multicast the Internet Group Management Protocol (IGMP) is utilized in order for membership of the multicast group to be established and coordinated. This leads to single copies of information being sent to the multicast sources over the network. Hence it’s the network that takes responsibility for replicating and forwarding the information to multiple recipients. By operating between the client and a local multicast router, IGMP utilises layer 2 switches with IGMP snooping and consequently derives the information regarding IGMP transactions. By being between the local and remote multicast routers, Multicast protocols such as PIM are then used to direct the traffic from the multicast server to the many multicast clients.

A typical IGMP architecture layout

In the context of VMware and virtual switches there’s no need for the vSwitches to perform IGMP snooping in order to recognise which VMs have IP multicast enabled. This is due to the ESX server having authoritative knowledge of the vNICs, so whenever a VM’s vNIC is configured for multicast the vSwitch automatically learns the multicast Ethernet group addresses associated with the VM. With the VMs using IGMP to join and leave multicast groups, the multicast routers send periodic membership queries while the ESX server allows these to pass through to the VMs. The VMs that have multicast subscriptions will in turn respond to the multicast router with their subscribed groups via IGMP membership reports. IGMP snooping in this case is done by the usual physical Layer 2 switches in the network so that they can learn which interfaces require forwarding of multicast group traffic. So when the vSwitch receives multicast traffic, it forwards copies of the traffic to the subscribed VMs in a similar way to Unicast i.e. based on destination MAC addresses. With the responsibility of tracking which vNIC is associated with which multicast group lying with the vSwitch, packets are only delivered to the relevant VMs.

Multicasting in a VMware context prior to SplitRXMode

While this method worked fine for some multicast applications this still wasn’t sufficient enough for the more demanding multicast applications and hence stalled their virtualisation. The reason being that in this case VMs would process the packet replication in a single shared context which ultimately led to constraints. This is because when there was a high VM to ESX ratio there was a consequent high packet rate that often caused large packet losses and bottlenecks. So with the release of vSphere 5, the new splitRXMode was released to not only compensate for this problem but also enable the virtualisation of demanding multicast applications. 

With SplitRXMode, the received packets are now split allowing them to be processed in multiple and separate contexts. This is achieved by having the packet replication conducted by the hypervisor instead. This is enabled by having multiple receivers on the same ESX server that consequently eliminates the requirement for a physical network to transfer multiple copies of the same packet. With the only caveat being that you require a VMXNET3 virtual NIC, SplitRXmode now uses multiple physical CPUs to process the network packets received in a single network queue. This feature can obviously improve network performance for certain workloads. Instead of a shared network queue, SplitRXmode enables you to specify which vNICs process the packets in a separate context, which consequently improves throughput and maximum packet rates for multicast workloads. While there may be some concerns that this could have significant CPU overhead, those that are running with Intel’s powerful new E5 processors should have little or no concern.

So if you’re considering multicast workloads, which have multiple and simultaneous network connections for your VMware environment e.g. (multiple VMs on the same ESX server that will receive multicast traffic from the same source), then take a closer look at SplitRXmode. If not, you might just like everybody else I’ve spoken to, completely forget about it.

CIO Success Simplified with Vblock

Of the many CIOs that I have had the pleasure to either work for or discuss with, one of the main concerns that constantly resonate is that of job longevity. When on average the job longevity for a CIO is between only 4-5 years and with trends showing that this is likely to shorten, it's no surprise that the role of a CIO requires instant success in minimal time and typically with minimal budget. Nearly every CEO’s mandate to a CIO is for IT to be better, faster and cheaper.

With this challenge the three steps to success for any CIO are plain and obvious. They are:

1) Eliminate risk
2) Improve Cycle Times
3) Reduce Cost 

While these three steps may incorporate subsidiary aspects such as demonstrating how IT best serves the business, building technological confidence to the business and making IT more effective etc. they eventually all fall under one of the three steps mentioned above.

Step 1: Eliminate Risk

Firstly by eliminating risk from your IT environment you immediately address the business concerns of:

-       The revenue impact of downtime
-       The revenue impact of performance slowdowns
-       The impact to the business’ brand value

Step 2: Improve Cycle Times

With a common business perception that legacy IT is too slow to deliver, improved cycle times are an imperative. This requires a solution that can accelerate the following and of course risk free:

-       Virtualisation and consolidation
-       Refresh projects
-       New Application and Service Roll outs
-       Private Cloud initiatives

Step 3: Reduce Cost

The last and most obvious one also presents the biggest challenge especially as customarily the last thing a new CIO can do is ask for a large investment to implement their new IT strategy. The business will quickly recognize a CIO’s success if they can prove that during their tenure they reduced CapEx and OpEx as well as Total Cost of Ownership.

CIOs shouldn't be concerned with buying tech from different silos & vendors but instead acquiring solutions that solve business problems

So it’s at this point imperative to remember that a CIO should not be concerned with buying technology from different silos and vendors but instead acquiring solutions that solve business problems. Long gone are the days when it was acceptable for a CIO to proudly boast the magnitude of their data centres and the large technology growth they had accumulated in an attempt to ensure everything was fully redundant. Instead the key drivers are for simplification, standardization & consolidation. This is where the concept of VCE's Vblock is key to a CIO’s success.

Infrastructure more often than not doesn’t carry the same sassiness or prominence to the business as a key application such as SAP but infrastructure is in essence the heart and soul of a business – if the server or storage goes down, the application won’t work which ultimately means you cannot ship and sell your product, hence why the three steps to CIO success are linked to a successful infrastructure.

How to Eliminate Risk:

An integrated stack should entail a robust disaster recovery and business continuity solution that can not only be tested and proven but also implemented and run with minimum complication.

This should also incorporate the de-risking of application migrations from physical to virtual platforms and more specifically key applications that the business depends on. 

Moreover this means a de-risked maintenance and operational procedure for the IT environment that is pretested, prevalidated and predictable and consequently eliminates any unplanned downtime.

In the past eliminating risk in this way has resulted in countless testing and validation procedures where every minute spent testing is a minute spent not growing the business. A true converged infrastructure can immediately resolve this.

How to improve Cycle Time:

Delivering a predefined, pre-integrated stack or in essence a plug and play data centre that’s delivered and built fit for purpose in typically only 30 days can quickly achieve this by reducing typical infrastructure delivery times by three months. Having proven infrastructure in minimal time allows the application owners to roll out new services at a fraction of the time and consequently cost.

How to Reduce Cost:

The key to this is to link any proposed investment to a tangible ROI that spans at least three years. Where most vendors have made the mistake of determining ROI based on virtualizing a total physical infrastructure this rarely works as most organisations have already virtualised to some extent. Instead an incremental value needs to be formulated that is linked to the virtualisation of key business critical applications.

Additionally with an integrated solution across the stack there’s no need to manage multiple components of an infrastructure and consequently multiple failure points that preoccupy multiple silos. This encompasses a changing of the mindset of technology being a break/fix, reactive organisation where heroes are rewarded for extinguishing fires. Instead a proactive and preventive methodology that has an “always on” culture will be adopted.
Vblock: Infrastructure delivered, deployed & optimized with minimum risk

By streamlining the workforce to do more with less in correlation with application teams, OpEx cost savings can quickly be achieved by redeploying money from the back end infrastructure to front office, revenue enhancing business value and productivity.

To conclude, technology’s protocol is to enable the business. Ensuring success in the three aforementioned steps enables a CIO to quickly enable the business …..and it may also allow them to stay in their job that little bit longer.