Persistent Storage (disk?) Requirements

(For The Low End ==the bottom 99%of the market)Jim Gray

Microsoft Research

The Ideal Disk

• Zero – Latency– Price– Power– Noise– Startup– Size

• Infinite– Capacity– Bandwidth– Shock– MTTF

What’s zero?What’s infinite?

• 1,000x more or less than current values

Smart Dust

• Zero volume (mm3)

• Zero power (uw)

• MB capacity

• Modest bandwidth, latency,…

• Cost a penny

• Probably mems or electronic.

• Trillions units/year

Cell Phone + PDA + Camera + GPS

• Zero volume (micro-drive is max)• Zero power (mw)• Zero noise • Instant on (1 second)• 10 GB capacity (camcorder)• Infinite shock• Modest bandwidth/latency (10MBps, 20ms)• Cost a few dollars• 1 billion units/year

Appliances/Games/Toys

• Small volume (2” drive is max)• 10GB – 1TB capacity • Zero noise • Instant on (1 second)• Infinite shock• Modest bandwidth/latency (10MBps, 20ms)• House power (so power not a problem)• Cost a few dollars• 1B units/year (games 10% of that)

TabletPC/Laptop

• Small volume (2” drive is max)• Less power than display or processor (100 mw)

• 1TB capacity (all my stuff)• Zero noise • Instant on (1 second)• Infinite shock• Modest bandwidth/latency (10MBps, 20ms)• Cost a few 10s of dollars• 300 million units/year

Servers(every client byte will be on several servers)

• 100TB capacity

• 1 hour scan time (==250MBps)

• 1 ms access time (1,000 aps)

• Infinite MTTF

• Low power/heat/cooling

• Low noise

• Cost a few 10s of dollars

• 1B units/year?

Things Microsoft Is Doing to Consume Disks

• Intelli-mirror: Transparent client state replication

• Terminal Server: Thin client

• Versioned file system just like VMS

• SnapShots: Copy On Write (COW) file system

• Disk replaces tape for backup• Easy remote replicas

– Database, Farsite,..

Things Microsoft Is Doing to Consume Disks

• Xbox (only game with a disk)• Video apps:

– Ultimate TV, PC TV, eHome (Free Style)

• Audio apps– Music (Media Player)– IP telephony, – voice recording in tablet, – Speech UI

• Photo apps:– Digital cameras ….

• Databases– Replication, Sequential search, autoManage

Things Microsoft Is Doing to Consume Disks

• Main thrust REDUCE MANAGEMENT COST

• Move from 100$/GB/y

To 100$/TB/y

• 1,000x improvement.