ESG Lab Spotlight NetApp Clustered Data ONTAP 8.2 Storage QoS Date: June 2013 Author: Tony Palmer, Senior Lab Analyst Abstract: This ESG Lab Spotlight explores how NetApp Data ONTAP 8.2 Storage QoS can help organizations create a highly efficient, flexible, and scalable data storage environment that supports a shared IT infrastructure foundation for non-disruptive operations, operational flexibility and efficiency, and on-demand IT services. The Challenges The demands on and for storage are increasing rapidly. To address data growth without interrupting business operations, rapid deployment of storage and IT resources to meet increasing demand becomes a function of scalability. ESG s 2013 IT Spending Intentions Survey revealed that, as they have been since 2010, increased use of server virtualization, improved backup and recovery, data growth management, and information security initiatives are all top 2013 IT priorities for the organizations responding to our survey. An increasing emphasis on cost and efficiency, and the near ubiquity of server virtualization are driving attention towards desktop virtualization and cloud infrastructure services. 1 Figure 1. Top IT Priorities Which of the following would you consider to be your organization s most important IT priorities over the next 12 months? (Percent of respondents, N=540, ten responses accepted) Information security initiatives Improve data backup and recovery Increased use of server virtualization Manage data growth Data center consolidation Desktop virtualization Use cloud infrastructure services Major application deployments or upgrades Business continuity/disaster recovery programs Improve collaboration capabilities 29% 27% 26% 25% 24% 22% 22% 22% 20% 20% 0% 5% 10% 15% 20% 25% 30% Source: Enterprise Strategy Group, 2013. 1 Source: ESG Research Report, 2013 IT Spending Intentions Survey, January 2013. The goal of ESG Lab reports is to educate IT professionals about data center technology products for companies of all types and sizes. ESG Lab reports are not meant to replace the evaluation process that should be conducted before making purchasing decisions, but rather to provide insight into these emerging technologies. Our objective is to go over some of the more valuable feature/functions of products, show how they can be used to solve real customer problems and identify any areas needing improvement. ESG Lab s expert third-party perspective is based on our own hands-on testing as well as on interviews with customers who use these products in production environments. This ESG Lab report was sponsored by NetApp.
ESG Spotlight: NetApp Clustered Data ONTAP 8.2 Storage QoS 2 As IT continues to implement advanced capabilities, as well as traditional services such as server virtualization, storage systems become more complex with tens or hundreds of thousands of LUNs, NFS and CIFS NAS shares, snapshots, and backups. This complexity is multiplied by the rapid growth of both the sheer number and the variety of different workloads which impose constraints on IT services. And with the transition to an IT-as-a-Service model, senior executives and line-of-business stakeholders are growing dependent on IT infrastructure and requiring IT to duplicate public cloud reliability and uptime. NetApp Clustered Data ONTAP 8.2 Storage QoS NetApp is addressing these challenges with clustered Data ONTAP 8.2, designed to deliver an on-demand, highly efficient, flexible, and scalable single storage operating system to help users manage data, application, and scale-out storage infrastructure growth. Clustered Data ONTAP 8.2 takes multiple NetApp storage systems and creates a massively scalable unified storage platform designed to provide nondisruptive operations, proven efficiency and seamless scalability for both enterprise and service-oriented infrastructures. Data ONTAP 8.2 provides scale-out storage that scales to petabytes of capacity and gigabytes per second of throughput using any combination of NetApp FAS or V-Series storage systems, configured in pairs for high availability. With clustered Data ONTAP 8.2, NetApp provides a host of enterprise-class capabilities that help storage administrators effectively manage their increasingly large and complex storage environments. Data ONTAP 8.2 focuses on providing a key set of capabilities to support changing IT infrastructure. These capabilities include: Non-disruptive operations in which the storage cluster can be scaled without service interruption, and physical resources can be easily kept in balance. Storage efficiency including deduplication, compression, and thin provisioning. Multivendor storage system virtualization incorporating third-party storage capacity into a Data ONTAP 8.2 cluster. Integrated data protection and disaster recovery. FlexClone which uses hardware to accelerate the creation of clones of data sets and VMs. Unified management of shared scale-out storage infrastructure. Secure multi-tenancy using Vserver to provide secure, protected access to groups of servers and applications. Storage quality of service which provides the ability to prevent rogue or runaway workloads from having an adverse impact on the performance of other workloads deployed on shared infrastructure. Storage QoS can also set specific service level objectives defining not to exceed performance at a tenant-level granularity. Storage Quality of Service (QoS) features are new in NetApp Data ONTAP 8.2. Storage QoS operates by applying policies (behaviors) on policy groups. These policy groups, which define isolation boundaries between workloads, operate within the scope of a Vserver (a Vserver is a NetApp virtual storage server, and can be used to provide multi-tenant separation) and can either contain a single Vserver, or one or more volumes, LUNS or VMDK files within the Vserver. In clustered Data ONTAP 8.2, policies supported are throughput limits, expressed either as or MB/sec, and are applied at the protocol stack, where by the throttling gets triggered when the aggregate throughput across all workloads within the policy group exceed the QoS limit. Storage QoS can be used to throttle and prevent rogue workloads from interfering with higher priority traffic, as well as to provide predefined service level objectives for specific tenants in service provider environments, and also to ensure consistent tenant-level performance regardless of the number of tenants deployed on the shared infrastructure.
ESG Lab Tested ESG Spotlight: NetApp Clustered Data ONTAP 8.2 Storage QoS 3 ESG Lab performed hands-on evaluation and testing of Storage QoS in clustered Data ONTAP 8.2 at NetApp headquarters, in Sunnyvale, California. Testing was designed to validate that QoS can limit the impact of a rogue application on system performance. Also of interest was validating the ability of Storage QoS to set performance limits on tenants in a service-provider environment. The configuration used in ESG Lab testing is shown in Figure 2. Eight virtual machines were installed on two servers in a VMware vsphere 5.1 cluster. Each VM was running Microsoft Server 2008 R2, and was connected via 10GbE to a 4-node NetApp Data ONTAP 8.2 cluster. Each of the 4 nodes in the NetApp cluster consisted of a NetApp FAS3220 storage system with 18TB of capacity for data stores. The NetApp cluster was configured with a single storage volume. Each VM was allocated a dedicated LUN from within this single volume. These LUNs were used as the data storage location for the VM s workload. Testing was conducted using the industry-standard Iometer test tool to both simulate workloads and create datasets. The simulation included two instances of Microsoft Exchange server and two instances of Microsoft SQL Server or SharePoint server, and two instances of a disk-to-disk backup application, storing backup data on the same storage system. Figure 2. The ESG Lab Test Bed Rogue Application In a rogue application scenario, the system is storing data for applications which are performing normally in a steady state. A rogue application starts and consumes excessive amounts of the storage system resources, affecting the performance of normal applications. ESG Lab simulated this scenario using the industry-standard Iometer test tool to create a steady state workload consisting of two virtual machines running a simulated Microsoft Exchange workload, and two virtual machines running a simulated Microsoft SQL database workload. The performance of the system running this steady state workload was captured. Next, a set of rogue applications was started. The rogue applications were simulated using Iometer on two virtual machines simulating a backup application. The performance of the system with the rogue application running was captured. Reviewing the throughput of all the applications, it was clear that the backup was consuming an inordinate amount of system resources, preventing the steady state workloads from meeting their users demands, as illustrated in Figure 3. A
ESG Spotlight: NetApp Clustered Data ONTAP 8.2 Storage QoS 4 limit of 25 MB/Sec was placed on the amount of bandwidth available to the backup applications. As soon as this limit was configured, the backup applications consumed fewer resources, and the Exchange and SQL server applications returned to their previous levels of performance. Figure 3. Bandwidth Consumption Steady State, Rogue Application, and QoS Applied During steady state operation, the Exchange servers were using approximately 26MB/sec of bandwidth, and the database servers were consuming approximately 27MB/sec of bandwidth. When the rogue backup application started, the backup consumed 234MB/sec of bandwidth, reducing the Exchange servers to 9MB/sec and the database servers to 7MB/sec. When a QoS limit of 25MB/sec was applied to the backup servers, the Exchange and database servers immediately experienced an increase in bandwidth, almost matching their previous levels, demonstrating how QoS can limit the impact of rogue applications on overall system performance. Table 1 details the performance of the system in steady state, with the rogue application, and with QoS applied. Performance for bandwidth in both and MB/sec is shown, along with the average response time in milliseconds. Table 1. Bandwidth Consumption Steady State, Rogue Application, and QoS Limiting Exchange Servers Database Servers Backup Servers Steady State Rogue Application QoS Applied MB/sec Average Response Time (ms) MB/sec Average Response Time (ms) MB/sec Average Response Time (ms) 829 26 19 294 9 54 851 27 19 3,512 27 9 893 7 36 2,904 23 11 3,736 234 9 400 25 80
Service Provider Model ESG Spotlight: NetApp Clustered Data ONTAP 8.2 Storage QoS 5 In the service provider model, the service provider pre-specifies service level objectives for each tenant. As organizations transition to an IT-as-a-Service model, IT duplicates the behavior of a service provider, and treats different business units, departments, and applications as individual tenants. The physical configuration used in ESG Lab testing for the service provider model is identical to the configuration used for rogue application testing, as shown in Figure 2. A logical configuration for the service provider model is shown in Figure 4. Three Vservers (NetApp virtual storage containers) were configured, and the application virtual machines were split among each Vserver. A Vserver and its associated virtual machines represent a tenant of the service provider, and all storage and operations are isolated. Two service level objectives (SLOs) were defined: Bronze (250 ), and Gold (1,000 ). Public service providers typically charge premiums for higher levels of service, while IT-as-a-Service would negotiate with the business stakeholder to determine the appropriate SLO. Each tenant Vserver was assigned a separate SLO. Figure 4. The ESG Lab Test Bed Service Provider Model To validate QoS operation in the service provider model, each tenant ran a simulated workload. Iometer was used to simulate Exchange 2010, SQL Server 2010, and backup workloads. The performance of the system was captured to understand the unrestrained resource consumption of the workloads. The QoS limits were then applied to each tenant Vserver, and the performance was measured again. The results are shown in Figure 5.
ESG Spotlight: NetApp Clustered Data ONTAP 8.2 Storage QoS 6 Figure 5. Service Provider Bandwidth Consumption Before and After QoS Limits Table 2 details the system performance before and after the QoS limits were applied. During steady state, unrestrained operation, tenant 1 and tenant 2 both consumed 1,041 (equivalent to 65MB/sec) while tenant 3 consumed 2,985 (equivalent to 144MB/sec). Both tenant 1 and tenant 2 were assigned the bronze SLO which would limit them to 250, and tenant 3 was assigned the gold SLO which would limit it to 1,000. As soon as the SLOs were assigned, performance of each tenant was immediately limited to exactly that specified in the SLO. Table 2. Service Provider Bandwidth Consumption Before and After QoS Limits Before QoS After QoS Throughput Throughput (MB/sec) (MB/sec) Tenant 1 1,041.69 65.11 249.91 15.62 Tenant 2 1,041.65 65.10 249.94 15.62 Tenant 3 2,985.31 144.08 999.52 34.61
ESG Spotlight: NetApp Clustered Data ONTAP 8.2 Storage QoS 7 Why This Matters As IT continues to implement advanced capabilities, as well as traditional services such as server virtualization, storage systems become more complex. This complexity is multiplied by the rapid growth in both the sheer number and the variety of different workloads which impose constraints on IT services. And with the transition to an IT-as-a-Service model, senior executives and line-of-business stakeholders are growing dependent on IT infrastructure and requiring IT to duplicate public cloud reliability and uptime. Storage QoS capability in NetApp Data ONTAP 8.2 enables customers to increase utilization of storage resources by consolidating multiple workloads in a single shared storage infrastructure, while minimizing the risk of workloads affecting each other s performance. Administrators can prevent tenants and applications from consuming all available resources in the storage infrastructure, improving the end-user experience and application uptime. In addition, predefining service level objectives allows IT to provide different levels of service to different stakeholders and applications, ensuring that the storage infrastructure continues to meet the business needs. ESG Lab validated that with Data ONTAP 8.2, it was easy to identify a rogue application that was affecting the performance of Exchange and database servers. This rogue application was limited to a specific throughput in MB/sec, and, instantaneously, the performance of the exchange and database servers returned to their prior levels. ESG Lab also validated QoS in a service-provider environment, which was modeled with three tenants isolated by three separate Vservers. Pre-specified service level objectives were applied to each Vserver and, regardless of the workloads of the tenants, no tenant exceeded its specified service level.
The Bigger Truth ESG Spotlight: NetApp Clustered Data ONTAP 8.2 Storage QoS 8 Applications critical to businesses, along with the ever expanding use of virtualization, and the transition to the cloud model of IT-as-a-Service are putting increasing demands on storage infrastructure, which must be able to support both increased scalability and increased reliability. The top ten IT priorities reported by respondents, as revealed in ESG s 2013 IT Spending Intentions Survey, are all affected by scalability and reliability. Storage Quality of Service is a methodology for IT to improve scalability and reliability by ensuring that storage infrastructure resources are properly utilized, and that rogue applications do not affect business-critical services. And as IT transitions to the cloud, quality of service can be implemented to ensure the appropriate service level objectives for different tenants in multi-tenant environments. NetApp has integrated QoS directly into clustered Data ONTAP 8.2, enabling administrators to set service level objectives defining not to exceed performance at the file, LUN, volume, or Vserver (virtual storage server container) level. Policies can be pre-specified and applied to different Vservers, enabling rapid customization of service levels in a multi-tenant environment. In addition, rogue applications that consume too many system resources can be rapidly identified and corralled by setting or MB/sec limits, ensuring non-disruptive operation of the storage infrastructure. ESG Lab was able to rapidly identify a rogue application, determine an appropriate throughput level, and set limits on that application, ensuring that business-critical applications such as Microsoft Exchange and OLTP databases continued to operate with adequate response time from the storage system. ESG Lab was also able to simulate a multi-tenant service provider environment, with pre-specified service level objectives. These objectives were applied to Vserver containers, and Data ONTAP 8.2 QoS limited throughput quickly and accurately. With the transition to the cloud model, users self-provision storage and other IT infrastructure components, and IT is often not aware of specific applications and user demands on the system. When these unknown or unforeseen applications consume more than their fair share of resources, IT must be able to quickly respond and adapt the system to ensure that business-critical systems are not impacted. Storage QoS is a key feature of clustered Data ONTAP 8.2, providing IT the visibility and control needed to corral rogue applications and to set and enforce service level objectives for a cloud or multi-tenanted environment, while enabling the appropriate resources to be dedicated to the appropriate tasks.
ESG Spotlight: NetApp Clustered Data ONTAP 8.2 Storage QoS 9 Appendix Table 3. ESG Lab Test Bed Data ONTAP 8.2 Cluster Hardware Software FAS3220AE (Qty: 4) 3U chassis One controller One 4 slot IO Expansion Module 2 x dual port 10GbE adapters 1 x 512GB Flash Cache card 1 x quad port SAS HBA 1 x DS4243 with 24 x 1TB SATA disks VM Cluster VMware vcenter 5.1 VM Operating System Windows Server 2008 R2 64-bit Workload generator Iometer All trademark names are property of their respective companies. Information contained in this publication has been obtained by sources The Enterprise Strategy Group (ESG) considers to be reliable but is not warranted by ESG. This publication may contain opinions of ESG, which are subject to change from time to time. This publication is copyrighted by The Enterprise Strategy Group, Inc. Any reproduction or redistribution of this publication, in whole or in part, whether in hard-copy format, electronically, or otherwise to persons not authorized to receive it, without the express consent of The Enterprise Strategy Group, Inc., is in violation of U.S. copyright law and will be subject to an action for civil damages and, if applicable, criminal prosecution. Should you have any questions, please contact ESG Client Relations at 508.482.0188.