Presentation Description



Presentation Transcript


SEMINAR PRESENTATION ON RAID Department of Computer Technology Y.C.C.E, NAGPUR


OUTLINE Introduction Types of RAID RAID standard level RAID implementation Applications Conclusion References


INTRODUCTION Redundant Array of Independent Disks [2] - RAID is a great system for increasing speed and availability of data. - Fulfils the needs of multimedia and other data hungry programs. - Provides fault tolerance.

Why Use RAID? :

Why Use RAID? RAID devices can act as a single drive. Allows simultaneous read/write. Overall increase in I/O performance. Provides data redundancy.


History Single large expensive disks (SLED). IBM and Berkeley University, California [3] RAID levels 0-5

Types of RAID:

Types of RAID Software RAID [1] -run on the server’s CPU -directly dependent on server CPU performance and load -occupies host system memory and CPU operation, degrading server performance Hardware RAID [1] -run on the RAID controller’s CPU -does not occupy any host system memory. - true hardware multi-tasking

RAID standard levels[4]:

RAID standard levels [4] RAID 0 RAID 1 RAID 2 RAID 3 RAID 4 RAID 5


RAID 0 Uses striping I/O performance gain No Data redundancy Not fault tolerant Not considered “true” RAID

Advantages and Disadvantages:

Advantages and Disadvantages Advantages -increased storage performance -no loss in data capacity Disadvantages -no redundancy of data


RAID 1 Uses mirroring Also known as duplexing Fault tolerant High Disk overhead Mirroring typically handled system software Simplest RAID design

Advantages and Disadvantages:

Advantages and Disadvantages Advantages -provides full redundancy of data Disadvantages -storage capacity is only as large as smalllest drive -no performance increases -some downtime to change active drive during the failure


RAID 2 Error Detection and Correction Parity and Hamming Code ECC (Error Correction Code)


RAID 3 Exit Hamming Code, Enter XOR ( e X clusive OR ) XOR in Action: 0101 2 XOR 0011 2 = 0110 2 XOR Logic Table A XOR B R esult 0 0 0 0 1 1 1 0 1 1 1 0

Advantages and Disadvantages:

Advantages and Disadvantages Advantages - High Read/Write Transfer Rates -Disk failures don’t slow the system -Low Ratio of Data Disks to Parity Disks Disadvantages - Transaction rate slowed by Parity Disk -Complex Controller Design -Software Implementation


RAID 4 Offshoot of RAID 3 No Striping, Entire files written to individual disks Parity Data created on a sector-by-sector basis

Advantages and Disadvantages:

Advantages and Disadvantages Advantages - Very high read rates Disadvantages - Very slow write rates -Inefficient data recovery -Even more Complex Controller Design than RAID 3


RAID 5 Highest Read data transaction rate Medium Write data transaction rate Most complex controller design Used For Server Applications.

PowerPoint Presentation:

Software Outboard DASD Inboard DASD Disk controlers RAID Implementation [6]

Applications [7]:

Applications [7] Image editing. Accounting and Financial Systems . Video production and editing. Any application requiring high bandwidth.

Problems in RAID[5]:

Problems in RAID [5] Co-related failures Write cache reliability Equipment compatibility Recovery time is increasing Hardware labelling issue


Conclusion Grown more complex Large price range Huge step forward for industry Not for the masses yet


References Yuval, Fledel . Uri, Kanonov . Yuval, Elovici . Shlomi , Dolev . Chanan ,. "Google Android: A Comprehensive Security Assessment". IEEE Security & Privacy (IEEE) (in press). doi:10.1109/MSP.2010.2. ISSN 1540-7993 Howe, Denis, ed. Redundant Arrays of Independent Disks from FOLDOC . Imperial College Department of Computing. http :// /RAID David A. Patterson, Garth Gibson, and Randy H. Katz: A Case for Redundant Arrays of Inexpensive Disks (RAID). University of California Berkeley. 1988. "SNIA Dictionary". Retrieved 2010-08-24 Disk Failures in the Real World: What Does an MTTF of 1,000,000 Hours Mean to You? Bianca Schroeder and Garth A. Gibson "Using WindowsXP to Make RAID 5 Happen". Retrieved 2010-08-24.

Thank You!:

Thank You! QUESTIONS??

authorStream Live Help