Cisco's UCS - The Prime Choice for Cloud & Big Data Servers?

Back in March 2009, when Cisco announced the launch of their UCS platform and subsequent intention to enter the world of server hardware, eyebrows were raised including my own. There was never any disputing that the platform would be adopted by some customers, certainly after seeing how Cisco successfully gatecrashed the SAN market and initially knocked Brocade off their FC perch. We’d all witnessed how Cisco used its IP datacenter clout and ability to propose deals that packaged both SAN MDS and IP switches with a consequent single point of support to quickly take a lead in a new market. Indeed it was only after Brocade’s 2007 acquisition of McData and when Cisco started to focus on FCoE that Brocade regained their lead in FC SAN switch sales. Where mine and others’ doubts lay were whether the UCS was going to be good enough to compete with the already proven server platforms of HP, IBM and Dell. Well, roll on three years and the UCS now boasts 11,000 customers worldwide and an annual run rate of £822m making it the fastest growing product in Cisco’s history. Amazingly Cisco is already third in worldwide blade server market share with 11%, closely behind HP and IBM. So now with this week’s launch of the UCS’ third generation and its integration of the new Intel Xeon processor E5-2600, it’s time to accept that all doubts have been swiftly erased.

Unlike other server vendors, Cisco’s UCS launch was from a fresh-fields approach that recognized the industry’s shift towards server virtualization and consolidation. Not tied down by legacy architectures, Cisco entered the server market at the same time Intel launched their revolutionary Intel Xeon 5500 processors and immediately took advantage with their groundbreaking memory extension feature. By creating a way to map four distinct physical memory modules (DIMMs) to a single logical DIMM that would be seen by the processor’s memory channel, Cisco introduced a way to have 48 standard slots as opposed to the 12 found in normal servers. With the new B200 M3 blade server, there’s now support for up to 24 DIMM slots for memory running up to 1600 MHz and up to 384 GB of total memory as well as 80 Gbits per second of I/O bandwidth.This is even more impressive when you factor in that with the Cisco UCS 5108 Chassis also being able to accommodate up to eight of these blades, scalability can go up to a remarkable 320 per Cisco Unified Computing System. Added to this Cisco took convergence further by making FCoE the standard with Fabric Interconnects that not only acted as the brains for their servers but also helped centralize management. With the ability to unite up to 320 servers as a single system, they also supported line-rate, low latency lossless 10 Gigabit Ethernet as well as FCoE. This enabled a unified network connection for each blade server with just a wire-once 10Gigabit Ethernet FCoE downlink, reducing cable clutter and centralizing network management via the UCS Manager GUI. Now with the newly launched UCS 6296UP, the Fabric Interconnect will double the switching capacity of the UCS fabric from 960Gbps to 1.92Tbps as well as the number of ports from 48 to 96.
Cisco UCS' Memory Extension

Other features such as FEX introduced the ability to ease management. FEX (Fabric Extenders) are platforms that act almost like remote line cards for the parent Cisco Nexus switches. Hence the Fabric Extenders don’t perform any switching and are managed as an extension of the fabric interconnects. This enables the UCS to scale to many chassis without increasing the amount of switches, as switching is removed from the chassis. Furthermore there is no need for separate chassis management modules as the fabric extenders alongside the fabric interconnects manage the chassis’ fans, power supplies etc. This means there’s no requirement to individually manage each FEX as everything is inherited from the upstream switch therefore allowing you to simply plug in and play a FEX for a rack of pre-cabled servers. Regardless of configured policies, upgrading or deploying of new features would simply require a change on the upstream switch because the FEX inherits from the parent switch, leading everything to be automatically propagated across the racks of servers.

The UCS components

With the aforementioned B200 M3 blade, there is also two mezzanine I/O slots, one that is coincidentally used by the newly launched 1240 virtual interface card. The VIC1240 provides 40 Gbps capacity which can of course be sliced up into virtual interfaces delivering flexible bandwidth to the UCS blades. Moreover with a focus on virtualization and vSphere integration, the VIC 1240 implements Cisco’s VM-FEX and supports VMware's VMDirectPath with vMotion technology. The concept of VM-FEX is again centered on the key benefits of consolidation, this time around the management of both virtual and physical switches. With the advent of physical 10GB links being standard, VM-FEX enables end users to move away from the complexity of managing standard vSwitches and consequently a feature that was designed and introduced when 1GB links were the norm. It does this by providing VM virtual ports on the actual physical network switch hence avoiding the hypervisor’s virtual switch. The VM’s I/O is therefore sent directly to the physical switch, making the VM’s identity and positioning information known to the physical switch, eliminating local switching from the hypervisor. Unlike the common situation when trunking of the physical ports was a requirement to enable traffic between VMs on different physical hosts, the key point here is that the network configuration is now specific to that port. That means once you’ve assigned a VLAN to the physical interface, there is no need for trunking and you’ve also ensured network consistency across your ESX hosts. The VM-FEX feature also has two modes, the first mode being called emulated mode where the VM’s traffic is passed through the hypervisor kernel. The other ‘high-performance’ mode utilizes the VMDirectPath I/O and bypasses the hypervisor kernel going directly to the hardware resource associated with the VM.

High Performance Mode utilises VMware's VMDirectPath I/O feature
Interestingly the VMDirectPath I/O feature is another key vSphere technology that often gets overlooked but one that adds great benefit by allowing VMs to directly access hardware devices. First launched in vSphere 4.0, one of its limitations was that it didn’t allow you to vMotion the VM, which may explain its lack of adoption. Now though with vSphere 5.0 and the UCS, vMotion is supported. Here the VIC sends the VM’s I/O directly to the UCS fabric interconnect, which then offloads the VM’s traffic switching and policy enforcement. By interoperating with VMDirectPath the VIC transfers the I/O state of a VM as well as its network properties (VLAN, port security, rate limiting, QoS) to vCenter as it vMotions across ESX servers. So while you may not get an advantage on throughput, where VMDirectPath I/O’s advantage lies is in its ability to save on CPU workloads by freeing up CPU cycles that were needed for VM switching, making it ideal for very high packet rate workloads that need to sustain their performance. Of course you can also now transition the device from one that is paravirtualized to one that is directly accessed and the other way around. VM-FEX basically merges the virtual access layer with the physical switch, empowering the admin to now provision and monitor from a consolidated point.

As well as blade servers, Cisco are also serving up (excuse the pun) new rack servers which update their C-class range; the 1U C220 M3 and the 2U C240 M3 server. With the announcement that the UCS Manager software running in the Fabric Interconnect will now be able to manage both blade and rack servers as a common entity, there is also news that this will eventually scale out as a single management domain for thousands of servers. Currently under the moniker of “Multi-UCS Manager”, the plan is to expand the current management domain limit of 320 servers to up to 10,000 servers spread across data centers around the world, empowering server admin to centrally deploy templates, policies, and profiles as well as manage and monitor all of their servers. This would of course bring huge dividends in terms of OPEX savings, improved automation and orchestration setting the UCS up as a very hard to ignore option in any new Cloud environment.
A single management pane for up to 10,000 servers

As well as Cloud deployments, the UCS is also being set up to play a key role in the explosion of big data. With the recent announcement that Greenplum and Cisco are finally teaming together to utilize the C-class rack servers, there is already talk of pre-configured Hadoop stacks. With Greenplum’s MR Hadoop distribution integrating with Cisco's C-class rack servers, it’s pretty obvious that the C-class UCS servers will also quickly gain traction in the market much like their B-series counterparts.

Incredibly it was not long ago that Cisco was just a networking company that’s main competitor was Brocade. Fast forward to March 2012 and Brocade’s CEO Mike Klayko is stating "If you can run Cisco products then you can run ours" to justify Brocade's IP credentials. When their once great competitor inadvertently admits they’re entering the IP world as a reaction to Cisco rather than a perceived demand from the market it really does showcase how far Cisco have come. It also speaks volumes that alternatively, Cisco proactively entered the server world when no perceived demand existed within that market. Three years later and with 11% market share and groundbreaking features built for the Cloud and Big Data, Cisco has moved far beyond its networking competitors and is well placed to be a mainstay powerhouse in the server milieu.