Persistent Storage disk Requirements For The Low

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, 000 x more or less than current values

Smart Dust • • Zero volume (mm 3) 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 (10 MBps, 20 ms) Cost a few dollars 1 billion units/year

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

Tablet. PC/Laptop • • • Small volume (2” drive is max) Less power than display or processor (100 mw) 1 TB capacity (all my stuff) Zero noise Instant on (1 second) Infinite shock Modest bandwidth/latency (10 MBps, 20 ms) Cost a few 10 s of dollars 300 million units/year

Servers (every client byte will be on several servers) • • 100 TB capacity 1 hour scan time (==250 MBps) 1 ms access time (1, 000 aps) Infinite MTTF Low power/heat/cooling Low noise Cost a few 10 s of dollars 1 B 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 • Snap. Shots: 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, e. Home (Free Style) • Audio apps – – Music (Media Player) IP telephony, voice recording in tablet, Speech UI • Photo apps: – Digital cameras …. • Databases – Replication, Sequential search, auto. Manage

Things Microsoft Is Doing to Consume Disks • Main thrust REDUCE MANAGEMENT COST • Move from 100$/GB/y To 100$/TB/y • 1, 000 x improvement.