Revolution in Storage James Hughes 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Agenda Economics Technology Shifts Open Questions Predictions 2 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Agenda Economics Technology Shifts Open Questions Predictions Prediction is very difficult, especially if it's about the future. Niels Bohr 2 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Demand for Storage The demand to store more data is not slowing down • Enabling new applications –Recording internet traffic –All CCTV surveillance for years • All human experience of 7B people is 1,000 EB Recording less valuable information “just in case” • The future value of information is not known All predictions that demand for computing or storage will be satisfied have all failed over the years 3 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Storage is a Price Elastic Market 4 http://en.wikipedia.org/wiki/Alfred_Marshall 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Storage is a Price Elastic Market Price elasticity of demand • Alfred Marshall (1890) 4 http://en.wikipedia.org/wiki/Alfred_Marshall 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Storage is a Price Elastic Market Price elasticity of demand • Alfred Marshall (1890) As the price of Storage approaches $0 • Demands for storage will approach infinity 4 http://en.wikipedia.org/wiki/Alfred_Marshall 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Storage is a Price Elastic Market Price elasticity of demand • Alfred Marshall (1890) As the price of Storage approaches $0 • Demands for storage will approach infinity If the price of a Cisco router approaches $0 • Demands for routers will not approach infinity 4 http://en.wikipedia.org/wiki/Alfred_Marshall 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Jevons Paradox • Cloud Computing increases the efficiency of computing.... Cloud Computing will increase this trend 5 http://en.wikipedia.org/wiki/Jevons_paradox 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Jevons Paradox • Cloud Computing increases the efficiency of computing.... Cloud Computing will increase this trend Improved technology doubles the amount of Information produced with a given amount of Storage Demand for Storage rises 5 http://en.wikipedia.org/wiki/Jevons_paradox 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Storage Technology Flash Devices HDD Futures Shingled Disks Log Structure Distributed Hash Tables Metadata Servers (not) Object Storage 6 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Moore’s Law for Flash Scaling http://upload.wikimedia.org/wikipedia/commons/6/64/NAND_scaling_timeline.png 7 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements http://cseweb.ucsd.edu/users/swanson/papers/FAST2012BleakFlash.pdf Flash Drive Density Forecast 8 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements http://cseweb.ucsd.edu/users/swanson/papers/FAST2012BleakFlash.pdf 2010 2013 Flash Drive Density Forecast 8 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Disk Performance Factor of 10x performance in 30 years • Processors are 1,000,000x in 30 years http://www.cs.princeton.edu/courses/archive/spr05/cos598E/bib/grochowski.pdf 9 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements 10 Areal Density Growth 0.1 1 10 100 1000 10000 100000 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 2015 2017 2019 year gigabit / in2 Single particle superparamagnetic limit (estimated) Charap’s limit (broken) •  Late 1990s – super paramagnetic limit demonstrated through modeling •  Perpendicular expected to extend to 0.5-1 Tb/in2 •  Additional innovations required at that point •  heat-assisted recording •  bit patterned media recording •  Areal Density CAGR 40% •  Transfer Rate CAGR 20% Perpendicular Writing & GMR HAMR HAMR +BPM •  Inductive Writing & Reading •  Inductive Writing/ MR reading •  Inductive Writing/ GMR reading 29% 100% 40% 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Shingled Disks Write head larger than read head • Turns Disk into a sequential media All updates to data and metadata are written sequentially to a continuous stream, called a log Disk API of sectors is no longer “natural” • One read may require several seeks http://www.ssrc.ucsc.edu/Papers/amer-ieeetm11.pdf 11 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Log Structured Storage How much is erased on a reposition? • Tape - the remainder of the tape • Singled disk - the remainder of the track group • Flash - the entire page All persistent Storage systems do/will implement log structure • e.g. “NoSQL Database of sectors” Does it make sense to layer a database on top of a database? • Could we use the log structure of the media to provide a more natural storage systems, not mimicking an antique paradigm? 12 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Leading to disaggregation of servers Single System Performance Trend http://web.eecs.umich.edu/~twenisch/papers/isca09-disaggregate.pdf 13 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Scaling Storage Distributed Hash Table • Key/Value Store RAM Memcached Flash Voldemort Disk Cassandra http://en.wikipedia.org/wiki/Distributed_hash_table 14 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Metadata Servers Required by traditional file systems (POSIX) to translate names to sectors • Hard to scale, heavy HA requirements, expensive Can we use a name as a key? • Place the data into a scaled key value store? • Eliminate costly metadata servers? 15 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Object Storage A storage system where objects (files) are read, written, replaced, but never changed. • e.g. Amazon S3 Allows log structure with a minimum of garbage collection New tier of storage • Lowest cost for online storage (not tape) • Huge aggregate performance (High throughput, OK latency) 16 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Open Questions Should system-level tiering decisions be automated or better left as an economic decision? • Is the complexity worth it Can Hadoop clusters be general purpose? • Amdahl’s Law Is there a general paradigm for turning drives off? • given complexity and access time 17 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Predictions Tape ➜ Log Structured B-Tree • Can allow multiple people to be streaming to the same tape creating independent file systems? • To aggregate key/value pairs? Distributed File System ➜ Scaled Object Store • Lower cost, higher performance RAM ➜ Remotely accessed as Key/Value Store • Implemented in hardware 18 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Conclusion Storage devices are continuing to get denser • Flash will not take over capacity disks for quite a while Object Stores are replacing Distributed File Systems • Success of S3 A Key/Value API for Storage • Reduces or eliminates the metadata server • More natural for the log structure of storage devices 19 

Seagate Confidential: Subject to NDA No. 77103, effective Jan. 18, 2009, and all applicable supplements Conclusion Storage devices are continuing to get denser • Flash will not take over capacity disks for quite a while Object Stores are replacing Distributed File Systems • Success of S3 A Key/Value API for Storage • Reduces or eliminates the metadata server • More natural for the log structure of storage devices 19 • Common API for disk, ram, flash, tape?