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

2. 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

3. 03 Magnetic Tape Storage 1 Advantages Development Linear recording
Helical recording
1 / 2 reel
Linear tape open

4. Access Patterns to a Hard Disk Drive
Research on access patterns on network attached storages (NAS) : * *

5. Origins of Data Loss Information storage is required : **

6. 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 *

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

8. Where are Magnetic Storages Used ?
World-wide enterprise disk storage consumption : * *

9. 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 *

10. Economics of Modern Storage
Multi-tiered storage can be economical : * *

11. 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.) *

12. 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 *

13. 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 *

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

15. 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 * *

16. 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 *

17. 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 *

18. Minimisation of Bit Errors
2 read / write heads : *
Two adjacent tracks with their azimuth angle at ± 20° *

19. 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) *

20. Development of a DDS Capacity doubles every 3 year : **

21. 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 *

22. 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. *

23. LTO Ultrium Roadmap *

24. 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 *

25. 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. *

26. 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 *

27. 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 *

28. 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 *