Skip to main content

RAID technology | DBMS - Computer science tutorial point


RAID (Redundant Array of Independent Disk)Technology


l A natural solution is a large array of small independent disks acting as a single higher-performance logical disk. A concept called data striping is used, which utilizes parallelism to improve disk performance.
l Data striping distributes data transparently over multiple disks to make them appear as a single large, fast disk. 

    Different raid organizations were defined based on different
    combinations of the two factors of granularity of data
    interleaving (striping) and pattern used to compute redundant
    information.
l Raid level 0 has no redundant data and hence has the best
     write performance.
l Raid level 1 uses mirrored disks.
l Raid level 2 uses memory-style redundancy by using
    Hamming codes, which contain parity bits for distinct
    overlapping subsets of components. Level 2 includes both
    error detection and correction.
l Raid level 3 uses a single parity disk relying on the disk
    controller to figure out which disk has failed.
l Raid Levels 4 and 5 use block-level data striping, with
    level 5 distributing data and parity information across all
    disks.
l Raid level 6 applies the so-called P + Q redundancy
    scheme using Reed-Soloman codes to protect against up
     to two disk failures by using just two redundant disks.
Use of RAID Technology 
Different raid organizations are being used under
different situations
l Raid level 1 (mirrored disks)is the easiest for rebuild of a disk from other disks– It is used for critical applications like l
   Raid level 2 uses memory-style redundancy by using Hamming codes, which contain parity bits for distinct overlapping subsets of components. Level 2 includes both error detection and correction.
l Raid level 3 ( single parity disks relying on the disk controller to figure out which disk has failed) and level 5 (block-level data striping) are preferred for Large volume storage, with level 3 giving higher transfer rates.
l Most popular uses of the RAID technology currently are: Level 0 (with striping), Level 1 (with mirroring) and Level 5 with an extra drive for parity.
l Design Decisions for RAID include – level of RAID, number of disks, choice of parity schemes, and grouping of disks for block-level striping.  

Labels:

Comments

Post a Comment

please subscribe my blog and let me suggest how I improve this site

Popular posts from this blog

Solve-write C program to find biggest number from three number by using nested if statement

          C program to find biggest number from three number                                                by using                                                                 nested if statement Problem Description This program takes the 3 numbers and finds the biggest among all. Problem Solution 1. Take the three numbers as input. 2. Check the first number if it greater than other two. 3. Repeat the step 2 for other two numbers. 4. Print the number which is greater among all and exit. Program codes:- here the program of finding biggest of three number run this in your Linux, DEV C++,turbo c++ #include<stdio.h> main() { int num1,num2,num3,big;   ...
Post a Comment
Read more

Minterm and maxterm in Digital logic design - Computer Science fundamentals tutorial

Minterm and Maxterm First thing to know before we proceed   towards   what is ‘minterm’ and ‘maxterm’ we have to know the sum of product and product of sum. Sum of product: - The logical sum of two or more logical product term is called sum of products expression. It is basically an OR operation of AND operated variables such as Y = AB+BC+ABC Product of Sum: - The logical product of two or more logical sum term is called product of sums expressions. It is basically an AND operation of OR operated variables such as Y = (A+B).(B+C).(A+B+C) Minterm: - Product term containing all the k variables of the functions is either complimented or uncomplimented form is Minterm. Canonical form of sum of product: - It is defined as the logical sum of all the minterms derived from the rows of a truth table for which value of the function is 1. It is called a minterm canonical form. The canonical sum of product expression can be given in a compact form by lis...
Post a Comment
Read more

Important MCQ of RDBMS( Relational database management system)-FCST

Important MCQ of RDBMS  1. A RDBMS consists a collection of ? a. Tables b. Fields c. Records d. Keys  ANS/- a. table 2. The term attribute refers to a ___________ of a table a. Record b. Tuple c. Column d. Key   ans/- c. Column 3. In relational model, the row of table is known to be ?  a. Relation b. Entity field c. Tuple d. Attribute  ans/- C. Tuple 4. . Address field of a person should not be part of primary key, since it is likely to ? a. Dependent b. Too long c. Changed d. Not changed  ans/- c. Changed 5. The relational model is concerned with ? a. Data structure and Data integrity b. Data Manipulation c. Both a and b d. None of these  ans/- c. Both a and b 6. Which is the false statement from the following ? a. A veiw is a named derived table b. A name relation is variable c. A veiw is a named reation and is virtual d. None of these  ans/- d. None of these 7. The union of primary key...
6 comments
Read more