Extreme Tiered Storage:Flash, Disk, and CloudStephen Foskett

Storage Expo NL, November 2009

Abstract

o The explosion of digital media and unstructured data is flooding modern storage systems. Although per-GB cost has dropped, enterprise storage costs remain high. Tiered storage has not reduced the costs fast enough, but a new concept holds promise. By leveraging the extreme performance of flash, the low cost of cloud, and advanced data movement technologies, extreme tiered storage can deliver the reduction in storage costs demanded by business. This session presents the business and technical issues and an architecture to address them.

You Have an Impossible Mission!

1. Reduce budgets

2. Improve performance

3. Meet business demands

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Storage Is Supposed To Be Getting Cheaper!

o Disk cost is dropping rapidly

o $250 buys:• 1994: 2 GB• 1999: 20 GB• 2004: 200 GB• 2009: 2000 GB

o But enterprise storage costs keep rising!

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Tiered Storage to the Rescue!

o Storage capacity just keeps expanding…• Larger files + More files = Growing volume of data

o IT responded by…• Consolidating on networked storage (SAN and NAS)• Experimenting with HSM and ILM• Tiered storage

o But…• Storage systems getting more complex and expensive• Management effort keeps growing• Cost savings aren’t materializing

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Where Is The Cost?

o Hardware and software make up a small percentage of total enterprise storage spending…

o …and hard disk drive capacity makes up a small percentage of that!

o Data center/environmental, administrative personnel, maintenance, and data protection are much bigger

o The biggest opportunity is inefficiency, but this has always been hard to tackle

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What If Disk Capacity Was Free?

o A thought experiment: What if disk space was free?o The cost of hard disk drives drops to zero tomorrow -

How will your usage patterns change?• Will you use more or less?• Will you manage capacity better or worse?• Will your storage budget shrink or grow?

o Surprise!• The cost of disk capacity is almost irrelevant to enterprise

storage budgets!• Even free disk capacity would not help save money, and it

might even make things worse

o Massive capacity growth is making free disk capacity a reality!

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Let’s Get Real!

o We need to tackle the real issues in storage:• Focus scarce management resources• Reduce budgets by tackling capacity utilization (finally!)• Improve data protection

o What’s stopping us?• Data just keeps growing• Mainstream technology hasn’t changed• Performance bottlenecks limit effectiveness• Always firefighting, never rebuilding

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Tiered Storage

Per

form

ance

an

d C

ost

Capacity

Fulfilling The Promise of Tiered Storage

o Tiered disk storage has not yet lived up to its promise• Small cost and

performance differential between FC and SATA disk

• TCO is very closeo SSD gives extreme

performance at high cost

o Cloud storage gives massive capacity at low cost

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Tiered Storage

FC

Disk

SATA

SSD

Cloud

Flash!

o The new (old) buzz• RAM vs. NAND flash vs. disk• EMC was first with “tier-0”• Sun, HP, NetApp adding flash to as a cache• Gear6 caches NAS with RAM• “Flash will replace high-speed disk”

o But…• Are they reliable?• Do they really perform that well?• Will you be able to use them?• Is the 10x-30x cost justified?• Do they really save power?

Is Flash Reliable Enough?

1 GB Thumb Drive

64 GB MacBook Air

146 GB Symmetrix

SSD

Capacity (MB) 977 62,500 142,578

Max. Write Rate (MB/s) 1 14 42 115

Min. Endurance (writes) 2 100,000 100,000 1,000,000

Capacity x EnduranceWrite Rate

7,000,000 seconds

149 million seconds

1.24 billion seconds

Minimum Lifespan at Max. Write Rate

81 days 4.7 years 39 years

Notes: 1 – No one writes this fast 24x7 2 – Manufacturers claim 2x to 10x better endurance

Does Flash Perform?

o Flash offers unique performance characteristicso Pro:

• Very fast random read with low latency and high consistency

• Low power consumption and heat, low weight, compact size

• High mechanical reliability

o Con:• Slower write performance, especially random• Write performance declines with use and capacity

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Flash Is Not A Disk

o Flash must be carefully engineered and integrated• Cache and intelligence to offset write penalty• Automatic block-level data placement to maximize ROI

o IF a system can do this, everything else improves• Overall system performance• Utilization of disk capacity• Space and power efficiency• Even system cost can improve!

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Then There’s Cloud Storage

o Like flash, cloud is currently over-hyped but also rapidly being adopted in the enterprise

o Like flash, cloud has unique performance characteristics and economics• Managed service versus purchased system• High-latency internet/HTTP access• Object store versus conventional NAS

o Like flash, cloud can make tiered storage a success• Powerful economics from fully-managed service and pay-

for-used pricing

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Public Cloud Storage Economics

o Just-in-Time Provisioning• Plan/buy for usage and not for peak capacity

o Fully Managed Storage• Managed GB = Power, space, cabling, racks, monitoring,

software, hardware, migration to new media… all included

o Enterprise Purchasing and Pricing Model• Flat, bundled price starts at $0.25/GB/month, $3K/TB/year• Enterprise sales, engineering, and support staff• Consulting and strategy available

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Data Types Suitable for Cloud Storage

Internal Storage Cloud Storage

Access Type Block LevelDatabases, ERP

File LevelUnstructured Data

Access Speeds Fiber Channel Gigabit Ethernet

Access Latency <10 ms <500 ms

Business DriverMission CriticalProduction DataTrade Secrets

ArchivalEncrypted

Collaborative

ExamplesERP, tape-out, design

flows, simulations, exchange server

email archives, database backups, video, image, media, personal drives

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Paths to the Cloud

Bringing Flash and Cloud to Disk

o Combining flash, cloud, and disk is radical but yields massive benefits• Each helps offset the shortcomings of the other and

magnify the overall result

o Integrated products are starting to appear but none are yet complete• Major disk vendors adding solid state disks and

automating volume-level tiering• Smaller companies are introducing integrated flash

caching and block-level tiering• Data movement vendors are adding cloud as a tier

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What’s Next?

o Flash and disk tiering will be fully integratedo Wide striping, thin provisioning, multi-parity, etc will

kill conventional RAIDo High-performance hard disk drives will disappearo VMware-specific storage systems will be on the

cutting edge of flash/disk integrationo Higher-level applications (archiving, content

management) will get integrated cloud storage firsto Fully-realized extreme tiered storage will be

available within three years

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Thank You!

Stephen Foskett

stephen@fosketts.net

twitter.com/sfoskett

+1(508)451-9532

blog.fosketts.net

GestaltIT.com

bit.ly/ESSBlog

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