Storage Tiering“…assigning the most reliable, high-performance equipment to support the most critical data, and the most cost-effective resources to support older, less critical information…”

Ken WaltersPBS

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Questions

>How many of you have a SAN?>If you don’t, do you think it

would be too expensive & complicated?

>If you do, are you using a single large array?

>Are you considering iSCSI?

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Agenda

>Definitions>Justifications>Background>Tiered Model>Enabling Technology>Deployment

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Definitions

>ATA/IDE (PATA)>SATA (Serial ATA)>SAS (Serial Attached SCSI)>FC (Serial SCSI)>SMB (Small/Medium Business)>SAN (Storage Area Network)>DAS (Direct Attached Storage)>Virtualization

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Justifications

>Lower disk costs> SATA vs. FC

>Lower connectivity costs> IP vs. FC

>Faster provisioning> CAT5 vs. FC, iSCSI vs. FC

>Improved Productivity>Foundation for ILM and Utility

Computing

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Background

>Concept has been around for a long time> Mainframe environment> Tape often a major component> Large amounts of data> Large amounts of money

>Not within reach of the SMB

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Background

>Changing Times> More being stored> Retention Periods> Disaster Recovery> Logging> Data mining> Regulations - HIPPA, SOX

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Background

>Typical SMB Data Center> Technologies not conducive to

efficient storage tiering: >Direct Attached Storage>Single array> Islands of storage

>NAS>DAS>SAN

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Background

>Typical SMB Data Center> “Many-hat” staffing

>No Storage Administrator

> DAS mindset> Distributed mindset

>Many servers each running one thing>Makes storage networking expensive

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Tiered Model

>Storage is heavily centralized and networked

>Storage is well virtualized> Storage arrays > In-band appliances > Gateways> Server side virtualization

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Tiered Model

>Multiple levels of storage > Differing performance > Differing availability> Differing Service Objectives

>Problem resolution>Backup and restore>Recovery Time Objective

(RTO)/Recovery Point Objective (RPO)

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Enabling Technologies

>IP Storage >Gateways>Inexpensive disks>Inexpensive arrays>Multi disk type arrays>Sophisticated Array Software>Storage friendly PNP operating

systems>Low cost SAN components>Zero Server Footprint arrays

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Deployment

>If you don’t have a SAN, build one and do it with iSCSI> Use FC only where you need it and make sure

you really need it.

>If you have a FC SAN, leverage it> Gateway iSCSI > Gateway NAS > Consolidate Storage Islands

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Deployment

>Replace equipment > Arrays that support FC and SATA under common

controllers (soon there will be SAS as well)> Software to migrate between tiers

>Augment by adding a new array to your SAN> SATA instead of FC

>Centralize Storage and attach as many servers as possible to drive down TCO

>Start deploying multiple tiers

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Time Check

>Still to go> Defining Tiers > Defining Availability> Implementing> Benefits

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Maple Syrup

> Grade A

> Grade B?

> Grade C?

> Grade A Light Amber

> Grade A Medium Amber

> Grade A Dark Amber

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Defining Tiers

> Avoid tier names that may disappoint> Determine the attributes based on solid business

analysis

 Availability

Performance Uses

AAA 99.99 HighOLTP, ERP, Decision Support, Messaging, Databases

AA 99.9 High/MediumFile Serving, Development, DR Mirrors, D2D Backup

A 99.8 Medium/LowArchiving, D2D Backup, Bulk Storage

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AAA - Defined

Availability 99.99

PerformanceHigh write and read performance, rapid rebuild

after disk failure

Disk Type FC, 15K, 73GB, 100% Duty Cycle

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AA - Defined

Availability 99.9

PerformanceRead performance high, write moderate, rebuild

time moderate

Disk Type FC/SATA, 15/7.2K, 73/250GB, 100% Duty Cycle

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A - Defined

> Consider RAID0 if you choose very large disks

Availability 99.8

Performance

Write performance low, read moderate, RAID5 rebuilds painfully slow. RAID0 may be a better choice, but no protection other than backups.

Disk TypeSATA, 7,200/5,400K, 250/320GB, Duty Cycle

30/50?/100?

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Measuring Availability

> Avoid targets in italics> People laugh at the top two now> You lose sleep with the bottom one> Cost of adding a “9” can be exponential

% Uptime % DowntimeDowntime per Year

Downtime per week

98% 2% 7.3 days 3 hrs 22 min

99% 1% 3.65 days 1 hr 41 min

99.8% 0.2% 17 hrs 30 min 20 min 10sec

99.9% 0.10% 8 hrs 45 min 10 min 5 sec

99.99% 0.01% 52.5 min 1 min

99.999% 0.001% 5.25 min 6 sec

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Availability & Service Levels>Defining availability targets is crucial

> Management approval> Everyone wants five nines until they see the

price tag. The operational costs can be staggering.

> Charge backs help people be realistic

>Use a Service Level Objective (SLO) not an Agreements

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Implementing Tiering

>Sell the idea to management>Classify your data

> Importance, security, lifespan, availability> Mission Critical, Business Critical, Operational

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Implementing Tiering

>Tier applications> Attributes include

> Performance> Availability> Recoverability > Security> Disaster recovery RPO/RTO

>Define storage tiers>Define server tiers

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Benefits of Tiering

>Highest availability does not become your lowest common denominator.

>Storage costs are in sync with value of data

>Concentrate money and staff where it is needed

>Staff Productivity>Tiered Storage is the foundation for

> Information Lifecycle Mgmt (90% process/10% technology)

> Utility Computing

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In Summary

>Build a SAN if you don’t have one>Use technology that supports tiering>Tier your storage and applications>Set availability & service levels>Sit back, save money and increase

productivity

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Resources

Web>snia.org/education>storagenetworking.org>searchstorage.techtarget.com>google.com

Books>Building Storage Networks – Marc Farley>Resilient Storage Networks – Greg P.

Schulz

Thank You!

kwalters@pbs.org