Stifling I/O bottlenecks, shrinking backup windows, and unplanned outages are commonplace concerns shared among data center architects rolling out their virtual data center and cloud.
Virtual machine (VM) growth tends to escalate as data centers get comfortable with virtualization technologies. But, growth often gets hampered by the lowest common denominator if not addressed as part of the implementation plan.
A few months back, I used the DeLorean with the flux capacitor from the old Back to the Future movies as an analogy to supercharging applications through data path optimization. Now, if you recall, in the second installment of this famed movie series, the fictional character Doc Brown went into the future to retrofit his DeLorean time machine with the power of flight. Similarly, upgrading your path management to optimize your virtual environment can make your data center seemingly levitate—and eliminate many of the concerns for virtual and cloud deployments.
Server virtualization is increasing as organizations realize gains through their virtual deployments. As recently noted by the Enterprise Strategy Group (ESG) research report “2012 IT Spending Intentions Survey”, about 30% of those queried cite increase use of server virtualization as their top spending priority for this year. Similarly, 30% also cite initiatives to improve data backup and recovery and 29% claim major application deployments or upgrades among the top priorities.
With increased server virtualization comes unabated VM sprawl. Rapid VM growth along with shifting VMs via VMware tools like vMotion can threaten service-levels with I/O bottlenecks impacting application availability and performance. As a data center architect, manager, or administrator, you need to be prepared to address the potential challenges virtualization might inflict on your business-critical applications.
Where Dreams Come True
Unlike somewhat static physical environments, manually mapping data paths across virtual environments can be very difficult given the dynamic nature of theses expansive deployments. What you need is a way to automate the management of your data paths to ensure a tuned environment and the best service levels for your user base.
EMC PowerPath/VE extends the power of the legacy EMC PowerPath Multipathing for physical environments to VMware vSphere environments. PowerPath/VE leverages the same patented algorithms as the legacy product to provide automated data path management, automated failover and recovery, optimized load balancing, and non-disruptive bus and path testing to virtual environments.
Similar to the previously published results for physical Windows environments, this time around ESG Lab tested PowerPath/VE for VMware vSphere with comparisons to the VMware native multipathing (NMP) that ships with the VMware hypervisor. Again, ESG Lab ran a number of their I/O profiles created using the Iometer workload generation utility to measure I/O per second (IOPS) in simulated Exchange data, OLTP, and file-serving workloads and throughput-intensive video-on-demand, decision support, and Exchange log workloads.
Though NMP provides a good baseline multipathing solution, PowerPath/VE takes it up more than a few notches with data path intelligence, automation, and optimization resulting in improved availability and better performance. While these test results represent what a user might experience, your actual results may vary though, from some recent customer conversations I’ve had, these performance results look to be the norm.
Let’s look at the test results in more detail.
As virtualization continues to grow, meeting daily backup windows seems to be an increasingly frequent challenge. Most backup applications use dedicated devices that transverse specific SAN data paths.
Applying PowerPath/VE with its optimized load balancing and VMware NMP set to the round-robin policy, ESG Lab determined that PowerPath/VE intelligent data path management made better use of available bandwidth for better IOPS performance, when faced with simulated backup workloads that created resource contention. PowerPath/VE handled 25% more IPOS versus NMP for 8K OLTP workloads, 17% more IOPS for file server, and 22% more IOPS for Exchange data base.
In a conversation with a customer who recently deployed PowerPath/VE, the administrator cited backups ending at 7:00 AM. Once I explained the potential impact on backup windows, he checked on recent activity and noted that data transfer seemed to now trail-off around 3:00 AM. This real world result suggests that his shop might be doing as well if not better than the numbers from the controlled tests.
While the back office needs to do daily backups that challenge resources, end-users can just as likely be the source of resource contention such as the common occurrence of users downloading large files that can bring overall performance to a crawl. In this test situation, the PowerPath/VE advantage over NMP was 24% for decision support, 143% for Exchange logs, and 138% for video-on-demand.
Similar to the conversation described above, when talking to another customer with a robust Exchange deployment, the storage architect noted a perceived performance gain around 2 times what he got out of Exchange in his virtual environment before he installed PowerPath/VE. Though his results closely match the lab results, it’ll be interesting to see what he measures for throughput with real analytical tools.
Sticking with the same customer, but a different metric, this same storage architect measured a 20% improvement in response time compared to the 18% faster response time measured with PowerPath/VE in the lab situation. These results show it is possible to achieve real-world results better than the simulated test results. Again, your mileage might vary.
While the ESG Lab hands-on testing focused on performance, these industry-analysts also took the time to review other capabilities such as installation and deployment, failover and recovery, and monitoring/management. Software download and install via integration with VMware vCenter was deemed flawless, as was the automated failover and recovery capabilities that embody the fundamental purpose of this multipathing product—application and data high availability. In addition, PowerPath Viewer for centralized, remote health monitoring got some well-deserved kudos for providing a detailed view into the SAN infrastructure.
What It Means
While it was bad enough in physical environments, the problems caused by oversubscribed ports, faulty HBAs, and flaky paths can be compounded when experienced in virtual environments.
The dynamic nature of virtual environments and cloud strongly suggests that if you automate your servers, you should automate your data path management to optimize your connections to your data storage and to eliminate the potential threat of I/O bottlenecks that could negatively impact application and data availability and performance.
For more information, read the ESG Lab Validation Report: EMC PowerPath/VE Automated Path Optimization for VMware Virtual Environments.