Astute Networks - Attacking Server Virtualization I/O Bottlenecks

For cash-strapped IT organizations, server virtualization has many compelling benefits, such as better use of IT assets and energy savings. But at some point, as the number of physical servers drops and the percentage of virtualized workloads and applications rises,application service-level performance suddenly goes to hell in a hand basket. I/O bottlenecks are the problem here, and Astute Networks has a solution in the form of a flash-memory-based appliance.

David Hill

August 26, 2011

5 Min Read
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For cash-strapped IT organizations, server virtualization seems to be a Monopoly-like “get out of jail free card” with many compelling benefits, such as better use of IT assets and energy savings. But at some point, as the number of physical servers drops and the percentage of virtualized workloads and applications rises, a perhaps strange and unexpected thing can happen: application service-level performance suddenly goes to hell in a hand basket. I/O bottlenecks are the problem here, and Astute Networks has a solution in the form of a flash-memory-based appliance.

The problem that Astute Networks, along with a number of other companies, attacks is a serious one. Often in IT, when we make the decision to adopt a new technology(such as server virtualization or cloud computing), unexpected obstacles occur midway through the process, hindering progress. The challenge is to solve those problems so continued adoption of a valuable technology goes on.

The problem of virtualization-related I/O bottlenecks is conceptually easy to explain. In non-virtualized IT environments, one application tended to run on one physical server and there was usually more than enough I/O bandwidth available to meet the responsetime requirements of applications. However, in the most ideal circumstances, you want to put as many virtual machines on a physical host server as possible. As the number of virtual machines rises on a single physical system, the aggregate I/O requirements of related applications (and that includes not only production applications, but also backup applications) can reach a point where a bottleneck occurs that seriously degradesapplication response time performance.

That tipping point may not be easy to determine a priori; one day you are doing fine, while the next day performance is terrible. This is a classic “knee of the curve” problem where the point beyond is one in which response time decays dramatically. However, understanding that you have an I/O queuing curve problem is a lot easier to detect than to solve. The simplest might be to backtrack and undo some of the virtual machines that you have already deployed, but this is unpalatable in the long run as it limits users toonly some of the benefits of server virtualization that they had hoped to capture.

Astute Networks’ answer to I/O bottlenecks is a software/hardware appliance called the ViSX G3. The appliance’s hardware is based on flash memory modules and uses what the company calls its DataPump Engine; a multi-protocol network-attached storage offload processor whose hardware, and software drive the flash memory module. The DataPump Engine processor accelerates TCP/IP network traffic, as well as iSCSIvirtualized data center traffic, while at the same time using flash memory to give a sustained high level of IOPS performance.

Competing flash solutions obviously exist, but Astute Networks feels that locating the appliance in the network as a complement to existing storage is superior to locating the flash module on the host or as DAS or network storage, as do some other vendors. Itfeels as if using internal PCI flash on host storage has limitations, such as fixed level of performance and performance limited to only one server. External flash as DAS storage has one of the same limitations as all flash is dedicated to one server. The other flash memory alternative, putting flash as a tier of SAN on network storage, does not get the most out of flash memory. I am sure that its competitors would disagree with thisassessment. The market will decide who is right, but Astute Networks makes a strong case for its approach.The fundamental question to consider is whether or not Astute’s ViSX solves the server virtualization I/O bottleneck. The answer, according to Walt Thinfen, VP andChief Information Officer for Visioneer, is an unqualified yes. Visioneer sells scanning products and uses a variety of common business applications in-house, such as SAPfor ERP, as well as Microsoft Exchange and SharePoint running on a 24x7 basis.

In an interview, Thinfen noted that Visioneer jumped on the server virtualization bandwagon three years ago, consolidating 165 physical servers onto just 4 physicalservers and reaping significant benefits, including green energy efficiency. Unfortunately, along the way, performance started to degrade, which was serious since one of the systems supported revenue-generating order entry processes.

A number of critical problems arose, including system timeouts and unacceptably slow response time for key applications. Thinfen didn’t want to go backwards and revert to more physical servers. Instead he sought an alternative that would eliminate the chokepoint on the I/O freeway and found it in Astute Networks’ appliance.

With the Astute Networks’ appliance, the bottleneck literally dissolved and Visioneer’s IT nightmare was over. Help desk tickets have gone down about 80%. Jobs that took four to six hours are now taking less than two hours. As Thinfen said to me, Visioneer is a happy camper because of Astute.

The world of IT is not an alternative reality, but it can offer a positive antidote to the reality of today’s news. IT technology has long delivered on numerous promises thatlead to a better world (at least from an unapologetic IT technologist’s perspective). Yet the promises of some technologies, such as server virtualization, can run intounexpected problems that have to be overcome.

The I/O bottleneck problem that occurs when businesses go after too much of a good thing (VMs on a physical server) often leads to the knee of the curve queuing problem and degraded service levels. Astute Networks’ ViSX G3network-based flash memory appliance leverages the company’s own home-grown software to reduce or eliminate I/O bottlenecks. With the help of Astute Networks, businesses can push I/O roadblocksout of the way and continue adopting and gaining the benefits of server-virtualization.

At the time of publication, Astute Networks is not a client of David Hill and the Mesabi Group.

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