Information Storage and Spintronics 03 Atsufumi Hirohata Department of Electronic Engineering 11:00 Wednesday, 03/October/2018 (SLB 210)

Quick Review over the Last Lecture Logical conjunctions : AND OR NOT NAND NOR XOR Notations : ¬A (Ā) A¯B A↑B A∧B A⊕B A∨B Venn diagrams : Logic circuits : A B A B A B A B A Ā A B

03 Magnetic Tape Storage 1 Advantages Development Linear recording Helical recording 1 / 2 reel Linear tape open

Access Patterns to a Hard Disk Drive Research on access patterns on network attached storages (NAS) : * * http://www.oracle.com/

Origins of Data Loss Information storage is required : * * http://www.oracle.com/

Why Tape Storage ? Magnetic tape media : * 3-times-more data are stored as compared with a hard disk drives (HDD). Almost 20 EB data are stored in tape media  Almost 25M tapes ! Tapes * http://home.jeita.or.jp/

Data Transfer Speed Magnetic tape media : * Without compression, 160 MB / sec. (576 GB / h). Almost comparable with a HDD HDD Tapes Optical disks * http://home.jeita.or.jp/

Where are Magnetic Storages Used ? World-wide enterprise disk storage consumption : * * http://home.jeita.or.jp/

Energy Consumption Energy costs : * Tape media : LTO-5 without compression Initial 3 PB data + 45 % annual increase for 12 years  Total cost of ownership (TCO) : 1/15 of HDD  Energy cost : 1/238 of HDD * http://home.jeita.or.jp/

Economics of Modern Storage Multi-tiered storage can be economical : * * http://www.oracle.com/

First Magnetic Tape Drive In 1951, Remington Rand introduced the first tape drive for a computer : * UNIVAC (Universal automatic computer) I uses a tape drive, UNISERVO. ½-inch wide tape Nickel-plated phosphor bronze (Vicalloy) 1,200 feet long 8 channels (6 for data, 1 for parity and 1 for timing) 100 inch / sec. (= 12,800 characters / sec.) * http://www.wikipedia.org/

IBM 7 Tracks In 1952, IBM also introduced a magnetic tape storage : * ½-inch wide tape 1,400 feet long 7 channels (6 for data and 1 for parity) 75 inch / sec. (= 7,500 characters / sec.) 6-bit characters In 1964, IBM introduced a 9 tracks : * ½-inch wide tape 2,400 feet long 9 channels (8 for data and 1 for parity) 200 inch / sec. (320 kB / sec.) 8-bit characters * http://www.wikipedia.org/

Linear Recording Method Data in long parallel tracks up to the tape length Multiple heads simultaneously write / read Very simple configuration Very low data density * http://www.wikipedia.org/

Linear Serpentine Recording In 1984, DEC introduced Digital Linear Tape (DLT) : * ½-inch wide tape Compac Tape I cartridge 45 kB / sec. * http://www.wikipedia.org/

Helical Scan Recording In 1956, Toshiba developed the first helical scan recording for a video tape recorder : * Tilt read / write head (drum) High-density recording * http://www.labguysworld.com/Cat_Toshiba.htm * http://www.wikipedia.org/

Advanced Intelligent Tape In 1996, Sony introduced Advanced Intelligent Tape (AIT) : * 8-mm wide tape 25 ~ 800 GB (without compression) 3 ~ 45 MB / sec. (without compression) Memory in cassette (MIC) : 64-kbit Electrically erasable programmable read-only memory (EEPROM) stores usage history and data address. ® Fast operation Adaptive lossless data compression (ALDC) : Data compression ~ 1/2.6. ® High recording density * http://www.wikipedia.org/

Digital Data Storage In 1987, Sony introduced Digital Audio Tape (DAT) : * Digital Data Storage (DDS) was then developed in 1989. 0.15-inch (3.81-mm) or 8-mm wide tape 60 ~ 170 m long 2 write heads at 6° angle with 9,000 rpm ~ 15 mm / sec. (0.18 ~ 12 MB / sec.) > 17M units shipped ~ 50 % in magnetic tape storage Mode motor Head cleaner Head cleaner (under the plate) Head Head Capstan roller Guiding roller Cassette cartridge * http://www.itmedia.co.jp/enterprise/articles/0607/13/news034.html

Minimisation of Bit Errors 2 read / write heads : * Two adjacent tracks with their azimuth angle at ± 20° * http://www.itmedia.co.jp/enterprise/articles/0607/13/news034.html

Head Configuration 2 pairs of read / write heads : * Write head Read head Metal-in-gap layer Non-magnetic ceramics Gap length Glass Magnetic ferrite core Magnetic lamination Data track width (DAT 72 = 5.4 mm) * http://www.itmedia.co.jp/enterprise/articles/0607/13/news034.html

Development of a DDS Capacity doubles every 3 year : * * http://www.itmedia.co.jp/enterprise/articles/0607/13/news034.html

Tape Cartridges One reel : * Two reels : * Tape is loaded into the system. Tape is loaded into the system. Head Tape is not loaded into the system. Exposed to a head * http://itpro.nikkeibp.co.jp/article/lecture/20061220/257427/

Linear Tape Open In 2000, IBM, HP and Seagate introduced Linear Tape Open (LTO) : * Based on research at IBM Tucson Laboratory DLT and AIT have dominated the market. Accelis : 8-mm wide tape 2 reels High access speed Resembles Sony AIT Ultrium : ½-inch wide tape 1 reels and linear scan Large storage capacity Resembles Quantum DLT 100 GB capacity (without compression) 20 MB / sec. * http://www.wikipedia.org/

LTO Ultrium Roadmap * http://www.ultrium.com/

High Fidelity Operation Read-while-write : * Written data is checked by reading out the data immediately after writing. Head module Tape motion direction Tape Written data Tracks Write head Read head * http://home.jeita.or.jp/

Written data with an error Rewrite Operation In case the read-while-write operation found an error : * Data is rewritten until the error disappears. Tape motion direction Tape Written data with an error Rewritten data Tracks Write head Read head Rewrite until the error disappears. * http://home.jeita.or.jp/

Data Distribution Operation Data subsets are repeatedly stored in various tracks : * Minimises a risk of data loss. Data subset “0” Error across tracks Track 1 Track 2 Track 3 Track 4 Track 5 Track 6 Track 7 Track 8 Error along a track * http://home.jeita.or.jp/

20 μm Precise Positioning Data subsets are repeatedly stored in various tracks : * Surface smoothness Tape width ~ 1.27 cm Data track 1280 20 μm Sapporo Tape length ~ 800 m Distribution in left / right Kagoshima * http://home.jeita.or.jp/

LTO Tape Media Track width of LTO tape media : * 12.65 mm wide tape / 1280 tracks Track width : 8.1 mm Top ferromagnetic layer Bottom non-magnetic layer Smooth base film (PET, PEN or PA) 70 ~ 80 % thickness Back coating Servo-signal Servo-band 320 320 1280 320 320 Track width : 8.1 mm * http://home.jeita.or.jp/