The Storage Capacity Design Dilemma an ITIL Approach

KT v01.14

EDUCATION

The Storage Capacity Design Dilemma an ITIL approach

LeRoy Budnik Knowledge Transfer KT v01.14 SNIA Legal Notice EDUCATION

• The material contained in this tutorial is copyrighted by the SNIA and portions are subject to other copyrights1. • Member companies and individuals may use this material in presentations and literature under the following conditions: – Any slide or slides used must be reproduced without modification – The SNIA must be acknowledged as source of any material used in the body of any document containing material from these presentations. – This specific legal notice shall not be removed. • This presentation is a project of the SNIA Education Committee.

The Storage Capacity Design Dilemma © 2007 Storage Networking Industry Association. All Rights Reserved. 1 © 1997-2007 Knowledge Transfer 2 KT v01.14 Abstract EDUCATION The Storage Capacity Design Dilemma

As architects, we must continually discover capability limits, constraints, and patterns and match requirements, capabilities and cost to provide an effective design. When we add the business requirements, it becomes the core mantra of ILM. Yet translating these requirements into hardware and software is not easy. In the process, we must continuously choose between complex alternatives, some of which seem equally unacceptable, and hence the dilemma. In this session, we will introduce fundamentals of storage infrastructure design from the perspective of ILM requirements. We will introduce key formulas, the science of storage capacity planning and follow a case study to demonstrate application in host, fabric and array design, to meet the requirements. The dilemmas of design decisions clear up once you know the formulas. It will change your thinking.

In this session, we have a dual focus on the science and consultative process of developing a mature discipline of storage capacity assessment, planning and design. The IT Information Library (ITIL) is the foundation of the methodology. Essential formulas come from a variety of sources.

Objectives: • Know basic storage capacity and performance formulas • Design for capacity and scalability in hosts, SAN, storage arrays and backup • Understand how to break out of the most common storage design dilemmas

GoalScopeNoWhy? text ToBusinessCapacity understand ManagementStrategy the andfuture Plan,ensures business IT Strategythat IT requirements,andprocess Plan and including storage the organization’s all capacity applications, provisioning operations andhardware,match IT evolvinginfrastructure O/S, businessnetworking, to ensure demand peripherals that in all a cost and currenthumaneffective resourcesand and future timely capacity manner and performance aspects of the business requirements are provided cost effectively.

OutputsServiceResourceNoBusinessInputs text Capacity CapacityCapacity Management ManagementManagement • Technology • Deployment and • CapacityMonitor,Trend, forecast, Plan analyze, mode, tunerun and andprototype,• reportProactivedevelopment report on onsize changes the plansand and and • CapacitystorageutilizationSLAs,document SLRs Databaseservice of ofand storagefuture Service performance (CDB) business components serviceprograms requirements improvements and Catalog • BaselinesEstablishtheir impact and baselines onprofiles storage and services •profiles• RevisedExpected, of operational use scheduled of the • Business plans and schedulechanges • Capacitystorage reportsservicescomponents (regular, strategy • Incidents and problems ad hoc and exception) • Effectiveness reviews • ManageIT plans and demand strategy for storage• Service services Reviews • SLA and SLR • Audit reports • SLA breaches • recommendationsBusiness requirements and transaction volumes • Financial plans • Costing and charging • Budgets • recommendationsOperational schedules

Management Activities EDUCATION

NoTechnicalCategorize text Metrics ProcessClassify Metrics • UtilizationBusiness • MTTPOpen • I/OsFunctional • MTTIClosed • BlockOperational Size • MTTM • Transfer Rates • MTBF/MTTR • Cost

NoCapacity text Plan Structure • Introduction • Scope • Methods • Assumptions • Management Summary • Business Scenarios • Storage Service Summary • Storage Resource summary • Options for Storage Service Improvement • Storage Cost Model • Recommendations

CostsBenefitsPossibleNo text Problems • Hardware,IncreasedCustomer expectations efficiencysoftware andand exceed toolscost savings technical capacity • ProjectOver– Deferred expectation management expenditure of tuning benefits – Economic provisioning • StaffUnrealistic and unachievable performance targets – Planned purchasing • Over optimistic vendor estimates • AccommodationReduced risk • Lack of Information • Confident forecasts No text • Reliance on Linear Prediction • Proven value to application lifecycle

• Capacity Management – DefineReview monitoring what exists points as a planned event! – Locate the Capacity data • Plan the process – Integrate into other planning processes – TrainSeek thebusiness staff • Synchronize with the – confidenceEstablish timeline levels and – Establish monitoring and budget cycle place components – integratedIdentify infrastructure data collection for delivering the volatility (probability) • Implement the process – CapacityExpand to Plan include: – Business Capacity – Service Capacity – Resource Capacity The Storage Capacity Design Dilemma © 2007 Storage Networking Industry Association. All Rights Reserved. 13 KT v01.14 Process Review EDUCATION

ReviewValidateCriticalKeyNo text Performance SuccessGoals Metrics Factors Indicators • IsAccurateCalculationsResource required business forecastsoutput and formulas available forecasts at the required times for • KnowledgeComponenttheTechnology appropriate ofutilization IT audience strategy and plans, and that the • Acceptable data collection • IsplansCost-effectiveness it’s activitiesare accurate cost effective? • UnderstandingAccuracy of tuning of current predictions and future technologies • Measurement of accuracy of match between • withinAre potential the capacity and actual management breaches team predicted and IT Storage Capacity and Business Need. • Abilityassociated to demonstrate with full notification? cost effectiveness • Are imposed constraints within acceptable client limits? • Interaction with other Service Management processes • Is reporting regular and on time? • Storage capacity matches business need • Is the capacity plan produced on time? • Are recommendations clear and accurate? The Storage Capacity Design Dilemma © 2007 Storage Networking Industry Association. All Rights Reserved. 14 KT v01.14 Capacity Process Interfaces EDUCATION

ResponsibilitiesCapacityStorage Team:Manager:Capacity include focus (1)(2) areas:: •• ProduceTestOftenMatchesProduce performance split storagestorageand into maintain performance capacitycapacity of new storage storage plansand monitoring demand capacity systems byand plan •• ProduceRecommendcapacityincreasingMonitor storageplanningstorage or managing servicemanagement availablelevels reports •• SizestorageRecommend– Tuning new capacity storageand storagedesign systems improvementstuning •• AssessEnsuringManage– Resolution new storagethat technology toexisting performance demand storage problems capacity is used optimally •• ImplementRecommend– Use of demand service storage managementlevel capacity reporting of capacity • PredictStudiesenhancements demandas required for storage services •• DetermineAccount for that workload storage changes service levels are maintainedin storage serviceand cost level justified targets

EDUCATION

Knowledge Statements

Assessment is a systematic approach to enable diverse requirements, including availability, capacity, cost, compliance and governance to be met over time. The process achieves alignment at best cost by summarizing requirements and matching them to capabilities at each requirement state change. The range of solutions available are limited by the value of information, with the goal of minimizing budgets, both capital and expense.

A storage tier is a collection of storage capacity that meets requirements with a consistent set of attributes, capabilities and characteristics which may include: • Availability • Performance Storage Tier ≠ Storage Service • Quality of Service • Cost

For example: it is possible that disks in the same array might be treated as different tiers because of RAID Level, data location on a spindle or other characteristics – the choice is yours…

Business View EDUCATION

Technical View EDUCATION

EDUCATION

Now for something more: technical . . .

Storage Perspective User Perspective (SRM) • Block • Allocated • Storage Pool – Static – Given set of capabilities – Dynamic – Quality of Service Range – Virtual – Pools are described by: • Available • Total Managed Storage – Mapped • Remaining Managed – Unmapped Storage • Used, Free, Total, Reserved • Primordial Pool – Total System Size (Raw) • Concrete Pool • Blocks, Metadata and Reported Capacity

(Queuing Theory) EDUCATION

arrivals and response time EDUCATION

Requirements EDUCATION Performance requirements Other requirements • I/Os per second (average/peak) • Retention – Bandwidth (average/peak) – Retention period/Expiration date – Jitter (range/mean+std. Deviation) – Disposition (erase/shred/archive, …) – Isochronous • Scalability (is this an SLO?) • Access requirements – Initial size (+Max. size) – MTFB (initial access time) – Size growth % per time period – Locking (concurrent access) – Bandwidth growth % per time period – File system affinity • Format • Security requirements – Record vs. byte stream vs. ? – Encryption level – Media portability – Integrity – Indelibility • Co-location/Separation (for association) • Load characterization – Level (host/datacenter/geographic) – Random read vs. write % – Co-operation – Sequential read vs. write % – Block size distribution • Price

• Growth (Capacity: Size) – Normal: Trend, Horizontal, Vertical (account for each) – Burst: Aggregation, Consolidation, Integration – Special Cases: Line Items/Transactions • Performance (Capacity: Performance, Workload Response) – General metric is response time (RT) • Availability • Manageability (Financial: Cost) – How many people does it take?

• Please send any questions or comments on this presentation to SNIA: [email protected]

Many thanks to the following individuals for their contributions to this tutorial. SNIA Education Committee

LeRoy Budnik, Knowledge Transfer Phil Huml, Knowledge Transfer Bob Rogers, Application Matrix