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IRAM Vision Statement Microprocessor & DRAM on a single chip: L o f g a i b c Proc $ $ – 10X capacity vs. DRAM I/O I/O L2$ Bus – on-chip memory latency Bus 5-10X, bandwidth 50-100X D R A M – improve energy efficiency 2X-4X (no off-chip bus) I/O – serial I/O 5-10X v. buses I/O Proc – smaller board area/volume Bus – adjustable memory size/width • Most transistors per D R A M Microprocessor in 1 year? D Rf Aa Mb Slide 1 V-IRAM1: 0.18 µm, Fast Logic, 200 MHz 1.6 GFLOPS(64b)/6.4 GOPS(16b)/32MB 4 x 64 or 8 x 32 or 16 x 16 + x 2-way Superscalar Processor I/O Vector Instruction Queue I/O ÷ Load/Store Vector Registers 16K I cache 16K D cache 4 x 64 4 x 64 Serial I/O Memory Crossbar Switch M I/O M 4…x 64 I/O M M M M M M M … M 4…x 64 M x 64 … 4… … M M M M M M M M M 4…x 64 M M M M M … M 4… x 64 … M M M M … Slide 2 IRAM Statistics • 2 Watts, 3 GOPS, Multimedia ready (including memory) AND can compile for it • 150 Million transistors – Intel @ 50M? • • • • Industrial strength compilers Tape out March 2001? 6 grad students Thanks to – – – – – DARPA: fund effort IBM: donate masks, fab Avanti: donate CAD tools MIPS: donate MIPS core Cray: Compilers Slide 3 Big Fat Web Servers • Maintenance is the challenge, as well as availablility and growth • Says who: – Lampson in keynote address at SOSP – Hennessy in kenote address at ISCA – Gray in Turing Award address • 2X HW costs and 1/2 maintenance cost is a big win Slide 4 Intelligent Storage Project Goals • ISTORE: a hardware/software architecture for building scaleable, self-maintaining storage – An introspective system: it monitors itself and acts on its observations • Self-maintenance: does not rely on administrators to configure, monitor, or tune system Slide 5 ISTORE-I Hardware • ISTORE uses “intelligent” hardware Intelligent Chassis: scaleable, redundant, fast network + UPS CPU, memory, NI Device Intelligent Disk “Brick”: a disk, plus a fast embedded CPU, memory, and redundant network interfaces Slide 6 ISTORE-II Hardware Vision • System-on-a-chip enables computer, memory, redundant network interfaces without significantly increasing size of disk • Target for + 5-7 years: • 1999 IBM MicroDrive: – 1.7” x 1.4” x 0.2” (43 mm x 36 mm x 5 mm) – 340 MB, 5400 RPM, 5 MB/s, 15 ms seek • 2006 MicroDrive? – 9 GB, 50 MB/s (1.6X/yr capacity, 1.4X/yr BW) Slide 7 • ISTORE node 2006 ISTORE – Add 20% pad to MicroDrive size for packaging, connectors – Then double thickness to add IRAM – 2.0” x 1.7” x 0.5” (51 mm x 43 mm x 13 mm) • Crossbar switches growing by Moore’s Law – 2x/1.5 yrs 4X transistors/3yrs – Crossbars grow by N2 2X switch/3yrs – 16 x 16 in 1999 64 x 64 in 2005 • ISTORE rack (19” x 33” x 84”) 1 tray (3” high) 16 x 32 512 ISTORE nodes / try • 20 trays+switches+UPS 10,240 ISTORE nodes / rack (!) Slide 8 Disk Limit: I/O Buses Cannot use 100% of bus Queuing Theory (< 70%) Command overhead (Effective size = size x Internal Memory C I/O bus 1.2) C External (PCI) I/O bus • Bus rate vs. Disk rate Multiple copies of data, SW layers CPU Memory bus – SCSI: Ultra2 (40 MHz), Wide (16 bit): 80 MByte/s – FC-AL: 1 Gbit/s = 125 MByte/s (single disk in 2002) C (SCSI) C Controllers(15 disks) Slide 9 Conclusion and Status 1/2 • IRAM attractive for both drivers of Next Generation: Mobile Consumer Electronic Devices and Scaleable Infrastructure – Small size, low power, high bandwidth • ISTORE: hardware/software architecture for single-use, introspective storage • Based on – intelligent, self-monitoring hardware – a virtual database of system status and statistics – a software toolkit that uses a domain-specific declarative language to specify integrity constraints • 1st HW Prototype being constructed; 1st SW Prototype just starting Slide 10 Backup Slides Slide 11 Related Work • ISTORE adds to several recent research efforts • Active Disks, NASD (UCSB, CMU) • Network service appliances (NetApp, Snap!, Qube, ...) • High availability systems (Compaq/Tandem, ...) • Adaptive systems (HP AutoRAID, M/S AutoAdmin, M/S Millennium) • Plug-and-play system construction (Jini, PC Plug&Play, ...) Slide 12 Other (Potential) Benefits of ISTORE • Scalability: add processing power, memory, network bandwidth as add disks • Smaller footprint vs. traditional server/disk • Less power – embedded processors vs. servers – spin down idle disks? • For decision-support or web-service applications, potentially better performance than traditional servers Slide 13 State of the Art: Seagate Cheetah 36 – 36.4 GB, 3.5 inch disk – 12 platters, 24 surfaces – 10,000 RPM – 18.3 to 28 MB/s internal media transfer rate (14 to 21 MB/s user data) – 9772 cylinders (tracks), (71,132,960 sectors total) – Avg. seek: read 5.2 ms, write 6.0 ms (Max. seek: 12/13,1 track: 0.6/0.9 ms) – $2100 or 17MB/$ (6¢/MB) (list price) – 0.15 ms controller time source: www.seagate.com Slide 14 TD Saw 2 Error Messages per Day • SCSI Error Messages: – Time Outs: Response: a BUS RESET command – Parity: Cause of an aborted request • Data Disk Error Messages: – Hardware Error: The command unsuccessfully terminated due to a non-recoverable HW failure. – Medium Error: The operation was unsuccessful due to a flaw in the medium (try reassigning sectors) – Recovered Error: The last command completed with the help of some error recovery at the target – Not Ready: The drive cannot be accessed Slide 15 Tertiary Disk SCSI Time Outs + Hardware Failures (m11) SCSI Bus 0 Disks SCSI Bus 0 Disk Hardware Failures SCSI Time Outs 10 9 8 7 6 5 4 3 2 1 0 8/15/9 8/17/9 8/19/9 8/21/9 8/23/9 8/25/9 8/27/9 8/29/9 8/31/9 8 0:00 8 0:00 8 0:00 8 0:00 8 0:00 8 0:00 8 0:00 8 0:00 8 0:00 Slide 16 Can we predict a disk failure? • Yes, look for Hardware Error messages – These messages lasted for 8 days between: »8-17-98 and 8-25-98 – On disk 9 there were: »1763 Hardware Error Messages, and »297 SCSI Timed Out Messages • On 8-28-98: Disk 9 on SCSI Bus 0 of m11 was “fired”, i.e. appeared it was about to fail, so it was swapped Slide 17 Tertiary Disk:SCSI Bus Parity Errors SCSI Bus 2 Disks SCSI Bus 2 SCSI Parity Errors 15 10 5 0 9/2/98 9/12/98 9/22/98 10/2/98 10/12/9 10/22/9 0:00 0:00 0:00 0:00 8 0:00 8 0:00 Slide 18 Can We Predict Other Kinds of Failures? • Yes, the flurry of parity errors on m2 occurred between: – 1-1-98 and 2-3-98, as well as – 9-3-98 and 10-12-98 • On 11-24-98 – m2 had a bad enclosure cables or connections defective – The enclosure was then replaced Slide 19 User Decision Support Demand vs. Processor speed Database demand: 2X / 9-12 months 100 “Greg’s Law” Database-Proc. Performance Gap: “Moore’s Law” CPU speed 2X / 18 months 10 1 1996 1997 1998 1999 2000 Slide 20