Nondisruptive Operations and Clustered Data ONTAP

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1 White Paper Nondisruptive Operations and Clustered Data ONTAP Arun Raman, Charlotte Brooks, NetApp January 2014 WP-7195

2 TABLE OF CONTENTS 1 Introduction Nondisruptive Operations (NDO) and Clustered Data ONTAP Planned Events Unplanned Events Protocols and NDO Windows File Services (WFS) Network File Services (NFS) Storage Area Network (SAN) Cost Savings from NDO Opportunity for Reinvestment (Opex Savings) Real Direct Savings (Capex Savings) Cost Avoidance Savings Case Study Conclusion LIST OF TABLES Table 1) Technology Refresh use cases and benefits Table 2) Maintenance operation use cases and benefits Table 3) Protection against unplanned events Table 4) NDO support matrix for different operations LIST OF FIGURES Figure 1) NDO and clustered Data ONTAP Nondisruptive Operations and Clustered Data ONTAP White Paper

3 1 Introduction As IT operations become more and more critical to business, no downtime can be tolerated. Downtime causes lost business, poor customer satisfaction, and competitive weakness. Today s always-on data centers are all about how the underlying infrastructure provides continuous data availability to the applications despite changing business needs. From a storage perspective, this means a flexible storage infrastructure, which allows businesses to start small and grow nondisruptively as the business grows. This flexibility reduces up-front costs and enables businesses to build their data infrastructure with no disruption to users or applications. 2 Nondisruptive Operations (NDO) and Clustered Data ONTAP NDO is not merely a feature or an attribute of clustered NetApp Data ONTAP ; it s an architectural vision for eliminating all forms of downtime from storage environments. Figure 1 classifies operations and events in the data center that typically incur downtime. This paper describes how clustered Data ONTAP can end downtime resulting from these events. Figure 1) NDO and clustered Data ONTAP Lifecycle operations are the operations that a customer performs to optimize the storage environment to meet business SLAs while maintaining a cost-optimized solution. These operations include moving datasets around the cluster to different tiers of storage and storage controllers to optimize the performance level of the dataset and to manage capacity allocations for the future growth of the dataset. Maintenance operations are operations during which components of the storage subsystem can be maintained or upgraded without incurring any data outage; for example, replacing a single hardware component such as a disk drive or shelf fan; or even replacing a complete controller, shelf, or system. The idea is that although data potentially lives forever, hardware does not, so maintenance and replacement of hardware will happen one or more times over the lifetime of a dataset. Infrastructure resiliency is the base building block for the storage subsystem; it prevents a customer from having an unplanned outage when a hardware or software failure occurs. Infrastructure resiliency is made up of redundant FRU components, multipath HA controller configurations, RAID, and NetApp WAFL (Write Anywhere File Layout) software enhancements that help prevent failures from a software 3 Nondisruptive Operations and Clustered Data ONTAP White Paper

4 perspective. For node hardware failures or software failures, HA failover allows a node in an HA pair to fail over to its partner. At a high level, there are two types of downtime unplanned and planned. Unplanned downtime is usually the result of component failure in the system, site failure, or human error; planned downtime is an activity that can be scheduled or planned. 2.1 Planned Events As critical as it is to protect against unplanned downtime, the most common form of downtime is the planned variety. By some estimates, 80% to 90% of all downtime in data centers is planned. Planned downtime falls into two categories maintenance operations (capacity and performance balancing) and lifecycle operations (technology refresh). Capacity and Performance Balancing Because of the difficulty of predicting future capacity and performance usage of applications and changing business needs, it is quite common for capacity or performance hot spots to emerge in a storage cluster. Usually, the organization s response to this unpredictability is to significantly overprovision storage, leading to wasteful underutilization of storage resources. Even when data migration is necessary, it usually requires application-level downtime. Given the frequency of capacity and performance bottleneck events (often weekly events in many customer environments), NetApp internal research suggests that nearly 40% of all benefits of NDO result from improving utilization from capacity or performance rebalancing. Technology Refresh Most hardware assets, including storage arrays, are on a 3-to-4-year depreciation cycle and are replaced by the latest gear available. This process usually involves copying existing data and migrating existing applications to the new array. Tech refresh is a top-of-mind storage initiative for administrators for multiple years running (source: The InfoPro Group). According to the same source, nearly 70% of all data migrations are done for tech refresh. Table 1) Technology Refresh use cases and benefits Capacity and Performance Balancing Use Case Clustered Data ONTAP, with its nondisruptive data migration capabilities, such as LIF migrate and NetApp DataMotion (VolMove), allows customers to remediate capacity or performance bottlenecks by moving them to another part of the cluster that has excess capacity or performance, thus avoiding application outage and reconfiguration and also leading to an overall dramatically higher level of storage utilization. Learn more Benefits Saves administrators time by eliminating the need for Negotiating downtime with application administrators Shutting down multiple apps Restarting multiple apps Verifying that everything is working correctly 4 Nondisruptive Operations and Clustered Data ONTAP White Paper

5 Storage Tiering Scale-Out Hardware Tech Refresh Data storage volumes are a dynamic resource for workloads. The required priority of any given volume is a function of the workload s SLA requirements and the capacity growth expectations. DataMotion for Volumes provides transparent movement of volumes to alternate resources within the cluster to accommodate the resource needs of the workload on the volume. Learn more DataMotion for Volumes allows customers to scale a storage system as needed by adding either new nodes or additional disk shelves and relocating data volumes to new hardware to balance provisioned resource pools on demand. Clustered Data ONTAP offers two solutions for doing tech refresh: Aggregate relocation (ARL) capability makes it possible to replace NetApp storage controllers nondisruptively without the need to copy data. Clustered Data ONTAP nondisruptive DataMotion for Volumes can be used to migrate existing data to new arrays. Learn more Accelerates the use of new hardware sooner: Tech refreshes are done in hours compared to weeks or months. Maintenance Operations Maintenance operations are typically done by using the built-in functionality of the storage array. They include operations such as software and firmware upgrades, as well as replacing broken components nondisruptively. Software and Firmware Upgrades Usually, each storage array has multiple types of firmware, such as disk firmware and shelf firmware. As new software revisions are released, the ability to upgrade all of these nondisruptively is essential. Clustered Data ONTAP has the ability to upgrade Data ONTAP as well as the disk and shelf firmware nondisruptively. Break, Fix, and Replace Operations Typically, when a component fails, a redundant component takes over to maintain high availability. However, at this point the storage array is running in degraded mode, leaving it susceptible to a 5 Nondisruptive Operations and Clustered Data ONTAP White Paper

6 secondary failure leading to outage. Therefore the ability to replace broken components nondisruptively is critical to maintaining redundancy and full availability. Clustered Data ONTAP makes it possible to nondisruptively replace storage controllers, subcomponents inside the controllers (such as HBAs, NICs, motherboard, NVRAM, and so on), switches, cables, and disks. Table 2) Maintenance operation use cases and benefits Use Case Benefits HA architecture offers easier software upgrade without the need for any downtime, Disk firmware, disk shelf firmware, and so on can be replaced nondisruptively. Software Upgrade Replace failed component Change configuration Learn more A failed component is taken over by a redundant component to maintain high availability. Failed components can be replaced nondisruptively, maintaining redundancy and full availability. Additional components can be added or upgraded to improve performance or add functionality. For example, NetApp Flash Cache can be added to a controller nondisruptively without the need for any application downtime. Eliminate deferred software and firmware upgrades. Be on the latest software faster. Saves administrators time by eliminating the need for Negotiating downtime with application administrators Shutting down multiple apps Restarting multiple apps Verifying that everything is working correctly Eliminate deferred maintenance and spend less time in degraded mode Eliminate deferred maintenance and apply changes immediately Nondisruptive shelf removal allows old disk shelves to be retired without the need to bring down the system. 2.2 Unplanned Events Historically, most storage (and even server or application) systems were designed to protect against unplanned downtime by eliminating all single points of failure and building redundancy at all levels. NetApp storage systems are no exception from redundant hardware components inside the storage 6 Nondisruptive Operations and Clustered Data ONTAP White Paper

7 controller to a dual controller HA architecture. Clustered Data ONTAP provides proven five 9 s availability, with less than 5 minutes of downtime per year. Table 3) Protection against unplanned events Storage Failures Disk Failures Resiliency High availability (HA) storage controller pairs, multipath HA, and alternate control path (ACP) eliminate any single points of failure, from host to data path. NetApp RAID-DP, ACP, persistent NVRAM write logs, service processor protection, and dual power supplies provide hardware availability. Learn more NetApp RAID-DP is an advanced RAID 6 technology. At a cost equal to or less than that of RAID 5 and with excellent performance, RAID- DP technology offers double-parity protection against data loss. In other words, RAID-DP enables peace of mind enterprise storage without compromise. Learn more Benefits Greater than five 9s availability No single point of failure Clustered Data ONTAP implements industry-standard Asymmetric Logical Unit Access (ALUA) to manage multiple I/O from host to storage and to handle path failures. Learn more Path failures 3 Protocols and NDO Nondisruptive operations are perceived differently by the client and by the application. Most protocols have built-in ability to handle some disruptions caused by data migration and switch-over, and to hide disruption from applications and users. Clustered Data ONTAP supports all common protocols (NFS, CIFS, FC, FCoE, and iscsi), and enhancements are made at both the protocol layer and the Data ONTAP layer to make it nondisruptive. 3.1 Windows File Services (WFS) SMB 3.0 for Microsoft Hyper-V and SQL Server environments with continuously available file shares support complete nondisruptive operations for all scenarios, including LIF migration, volume move, and storage failover and giveback. However due to SMB 1.0 and 2.0 protocol shortcomings, the client connections get dropped during LIF migration or storage failover, but they are nondisruptive for volume 7 Nondisruptive Operations and Clustered Data ONTAP White Paper

8 move operations. SMB 2.0 introduces durable file handles, which allow an application to use the existing open file handles after a LIF migration. In summary, the minimum requirement for NDO is SMB 2.0 or later. Learn more 3.2 Network File Services (NFS) NFS clients normally retry to connect to the storage. If the timeouts are configured correctly for the protocol and at the application level, NFS clients preserve nondisruptive operations. 3.3 Storage Area Network (SAN) Clustered Data ONTAP asymmetric active-active architecture is based on the ALUA standard. ALUA enables host multipath software to distinguish between optimized and unoptimized paths and to switch over to unoptimized active paths when the current active path is down due to failure or controller maintenance. Table 4) NDO support matrix for different operations Protocol LIF Migration Volume Move Failover and Giveback Aggregate Relocation (ARL) WFS P * P P ** P ** NFS P P P P SAN P P P P * Only SMB 2.0 and later are nondisruptive. ** Only SMB 3.0 with continually available file shares is nondisruptive. 4 Cost Savings from NDO Cost savings related to downtime have typically focused heavily on eliminating unplanned downtime by demonstrating savings related to avoiding lost employee productivity, lost revenue from unserved customers, loss of customers to competitors, damaged reputation, and so on. Although these savings are real and quantifiable, the impact of eliminating planned downtime is far more substantial: Based on our research, 70% to 80% of NDO benefits are achieved by enabling the elimination of planned downtime. These cost savings from eliminating planned downtime with clustered ONTAP fall into three categories: opex savings from improving administrator productivity, capex savings from increased utilization, and reduced risk from proactive maintenance and upgrades. 4.1 Opportunity for Reinvestment (Opex Savings) For planned downtime, the argument could be made that it can be scheduled at a relatively low-activity time of the day, week, or quarter, thus minimizing the impact to the organization and the end user. However, in a shared storage environment, coordinating these low-activity periods among multiple stakeholders is a difficult task. The actual outage requires effort from multiple administrators to shut down, verify, start up, verify, and so on. It may not even be possible to negotiate a suitable window for the downtime. 4.2 Real Direct Savings (Capex Savings) There are two sources of capex savings. First, nondisruptive data migration to remediate application capacity and performance bottlenecks allows customers to dramatically increase the overall utilization of their storage systems. 8 Nondisruptive Operations and Clustered Data ONTAP White Paper

9 The second source of capex savings is tech refresh. Without NDO and clustered Data ONTAP, newly purchased storage frequently sits boxed up, waiting for a window for downtime to install the new equipment, or for disruptive data migrations to be completed, while the clock has already started ticking on monthly maintenance charges and depreciation. 4.3 Cost Avoidance Savings The third source of NDO savings from eliminating planned downtime is reduction in risk. Being able to perform maintenance operations such as software and firmware upgrades, as well as replacing broken components proactively, significantly reduces the risk of unplanned downtime resulting from a secondary failure. Without NDO, these upgrades are often delayed for lack of a downtime maintenance window, making the storage system vulnerable to issues with known fixes. Similarly, the lack of maintenance windows forces customers to continue to run in degraded mode resulting from the failure of the primary component. Our research suggests that more than 20% of all savings from NDO are achieved by reducing the risk that results from deferred maintenance. 4.4 Case Study This case study examines the IT department of a large technology company. The company has 145 NetApp HA installations supported by 21 storage administrators and 21 application administrators. With 145 solutions, at least one maintenance activity is performed on an HA pair every week. Storage administrators must constantly negotiate with application administrators to get a common maintenance window for any planned activity, thus bringing down their productivity. Although the company s infrastructure met most of their business needs, the IT team wanted to adopt new technology that would serve the business needs much faster. The company s IT department focused on building a cost-competitive solution that meets business needs and also improves productivity of the administrators and increases operations margins. The IT department chose clustered Data ONTAP and immediately saw their administrators spending less time in negotiating for downtime. Although the maintenance operations continued to be performed during times of less activity, the hours of negotiation and the need to stop, start, and verify applications were completely eliminated. Table 2 shows the annual savings that the company realized in terms of administrator hours, capex expenditures, and risk avoidance. 9 Nondisruptive Operations and Clustered Data ONTAP White Paper

10 Savings ($) Savings (%) Opportunity for Reinvestment Clustered Data ONTAP allows maintenance and refresh activities to take place while the storage and its applications are active, without disrupting users. For storage and application administrators, this can eliminate the need to negotiate for downtime, and all the activities associated with shutting down and restarting applications are not required. $1,631,291 (26,100 hours) 30% Real Direct Savings With clustered Data ONTAP, because new controllers can be introduced into a cluster nondisruptively either in place of existing controllers (using aggregate relocation) or to expand and rebalance the existing cluster the newly purchased hardware assets can be put into service as soon as they are delivered. On average this adds 6 months to the productive life of a storage asset. Additionally, each new generation of storage arrays brings better performance and increased density, allowing multiple workloads to be consolidated on fewer controllers, resulting in space, power, and cooling savings. Cost Avoidance Savings Storage administrators used clustered Data ONTAP HA architecture to perform nondisruptive software and hardware upgrades and also to perform break, fix, and replace operations $1,524,234 37% $657,720 31% Assumptions: 2 hours spent by storage and application administrators on negotiating downtime 3 hours spent by application administrators for stopping, starting, and verifying applications Software and hardware upgraded once a quarter Applications rebalanced twice a year on average Average annual salary of an IT staff person = $125,000 Average life of storage controllers is 4 years Average of 10 applications run per HA pair 5 Conclusion NetApp s vision of NDO goes far beyond eliminating unplanned downtime or even common forms of planned downtime such as maintenance operations. It seeks to eliminate even the more common forms of downtime that result from lifecycle operations such as technology refresh and rebalancing for capacity and performance. Eliminating planned downtime reduces opex by eliminating the need for negotiating downtime windows, shutting down applications before a maintenance window, and restarting them afterward. Additionally, being able to carry out lifecycle operations nondisruptively helps reduce capex through improved utilization, better consolidation, and extending the useful life of new storage assets. Finally, being able to carry out maintenance operations proactively helps reduce the risk of unplanned downtime caused by secondary failure. 10 Nondisruptive Operations and Clustered Data ONTAP White Paper

11 Refer to the Interoperability Matrix Tool (IMT) on the NetApp Support site to validate that the exact product and feature versions described in this document are supported for your specific environment. The NetApp IMT defines the product components and versions that can be used to construct configurations that are supported by NetApp. Specific results depend on each customer's installation in accordance with published specifications. NetApp provides no representations or warranties regarding the accuracy, reliability, or serviceability of any information or recommendations provided in this publication, or with respect to any results that may be obtained by the use of the information or observance of any recommendations provided herein. The information in this document is distributed AS IS, and the use of this information or the implementation of any recommendations or techniques herein is a customer s responsibility and depends on the customer s ability to evaluate and integrate them into the customer s operational environment. This document and the information contained herein may be used solely in connection with the NetApp products discussed in this document NetApp, Inc. All rights reserved. No portions of this document may be reproduced without prior written consent of NetApp, Inc. Specifications are subject to change without notice. NetApp, the NetApp logo, Go further, faster, are trademarks or registered 11 Nondisruptive Operations trademarks and of Clustered NetApp, Inc. Data in ONTAP the United States and/or other countries. All other brands or products are trademarks or registered White Paper trademarks of their respective holders and should be treated as such. WP