Next Generation StorageTek Tape Drive: T9840C. James Cates Robert Raymond

Transcription

1 Next Generation StorageTek Tape Drive: T9840C James Cates Robert Raymond

2 StorageTek Tape Drives - A CHOICE Customers have a need for two different types of drives, which are ideallysuited for two different purposes: CAPACITY drives for High Capacity The StorageTek T9940 family of drives is designed and tuned for robust costeffective capacity applications High performance, single reel cartridge design ACCESS drives for Fast Data Retrieval The 9840 family of drives are designed and tuned for fast access, robust retrieval applications Maintains high performance dual reel cartridge design for all generations T9840C third generation drive in the 9840 family

3 Tape Path and Cartridge Types 9840 Single Hub External tape path Dual Hub Internal tape path No leader blocks

4 9840 Cartridge (no-covers) Idler Tape Guides Tape Reels Tape Path Compliant Tape Guide (Stationary) Compliant Tape Guide (Stationary)

5 9840 Cartridge Tape Guide Fixed Flange (Reference Edge) Media Compliant Spring

6 9840 Cartridge Demo Video Provided by Imation Corporation

7 Data Access Comparison Data Access: Time from cartridge insertion in drive to first byte of data - timed to mid-point and does not include robotic time Access Seconds T9840C 12 Capacity Seconds Single hub cartridge drives

8 9840 Family Specifications Parameters 9840A T9840B T9840C Capacity (native) 20 GB 20GB 40GB Data rate (native) 10MB/sec 19MB/sec 30MB/sec Access time Load Search Rewind 12 sec 4 sec 8 sec 16 sec 12 sec 4 sec 8 sec 16 sec 12 sec 4 sec 8 sec 16 sec FC speed 1 Gbit/sec Dual port 2 Gbit/sec Dual port 2 Gbit/sec Dual port Compression speed 35MB/sec 70+ MB/sec 70+ MB/sec Search velocity 8 m/sec 8 m/sec 8 m/sec Media MP1 MP1 MP1

9 T9840C Parameters Parameter T9840C # of Parallel Channels 16 Write Track Width (µm) 36 Read Track Width (µm) 17 KFCI KBPI Coding Efficiency 0.99 Number of Tracks 288 Tape Velocity (m/sec) 3.3

10 Cartridge Loading Assembly 9840 Tape Drive Electronic Module

11 9840 Electronic Module (4 Printed Wiring Board Assemblies) Read/Write Card Embedded Interface Card System Processing Card Power Distribution Card

12 Block Diagram of Data Stream Digital Processing Read/Write Channel Data Formating Write Driver ma per channel Write Elements Data Compression User Data Read Channel Detection Pre-Amp AGC & Filtering mv MR Read Elements Tape Head Media

13 Channel Electronics Write driver must be capable of delivering write currents of the order of up to 60 ma 0-pk per channel. Write current rise time required to be less than 5 ns. Analog pre-amps provide low noise amplification (50x to 100x) of the read signal from the head. Automatic gain control (AGC) is used to adjust for variations in signal amplitude and keep a fixed input signal to the read channel detection. Filtering is used to shape the waveforms for better detection. Read channel detection is dependent on the recording scheme.

14 T9840C PRML Channel Employs Overland Storage channel. Uses a EPR4 partial response target. Multiple diversity channels are used to address interchange, head wear and tape wear. One channel optimized for legacy read. is a trademark of Overland Storage. technology is used to achieve T9840C capacity and performance.

15 T9840C Servo Guiding Servo employed to accurately control position of head relative to media Magnetic servo pattern pre-written on tape Servo readers located on magnetic recording head Amplitude based servo using a checkerboard pattern

16 Ferrofluid/MFM Images of 9840 Data Tracks and Amplitude Based Servo Tracks servo tracks with bursts of servo signal. Servo head positions between tracks. 5 positions Direction of tape

17 Servo Patterns

18 T9840C Tape Head

19 Thin Film Write Head Cross-section

20 T9840C Head Design

21 T9840C Data Protection (ECC) 3 key designs protect customer data Reed Solomon Encoding (RS) Addition of bytes to customer bytes to enable recovery of customer bytes when some bytes are missing due to defects or damage to tape. Data Interleave and Rotation The distribution of Customer and RS bytes over a larger piece of the media, both down tape and across tape Sixteen Channel Recording Allow data to be distributed across the width of the tape

22 Reed Solomon Code Customer data bytes are taken 36 at a time; an Error Correction System adds 12 unique bytes to the 36 to form a special group of 48 bytes. This group is called a codeword. Customer Bytes ECC 48 byte CODEWORD A codeword, when read from media, has the following properties: if up to any 12 bytes are missing the remaining are used to re-create all 48 bytes - including the customers byte CODEWORD Customer Bytes ECC

23 Data Interleave and Rotation The distribution of Customer and RS bytes over a larger piece of the media, both down tape and across tape CODEWORD Servo tracks 16 Tracks ECC can recover if up to 4 out of the 16 tracks have errors Large Defects effect few bytes Tape Motion

24 T9840 Family Feature VolSafe.for Compliance Copies WORM (write once/read many) for Tape Same capacity standard cartridge Color cartridge markings to identify VolSafe Special label identification Drive identifies media as Append Only SEC certified solution for archive applications to US Government As an application in an existing library All you need is the cartridge!

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