Answer the following RAID-based questions: (a)What three common characteristics
ID: 2247522 • Letter: A
Question
Answer the following RAID-based questions:
(a)What three common characteristics are shared by all RAID levels except RAIDO?
(b) Assume a 10-drive RAID configuration. Fill in the following matrix, by indicating the relative rank (i.e., 2rd, 3rd etc.) of each level under each performance metric, Note that the highest performing level under each metric is given in the table by the notation 1 (1st) Please briefly justify your relative ranking.
RAID level
Storage Density
Bandwidth Performance
Transaction Performance
Redundancy
(reliability)
0
1(1st)
1(1st)
3
1(1st)
5
6
10
1(1st)
Storage density refers to the fraction of disk storage available for user data (as opposed to parity data). Bandwidth performance reflects how fast data can be transferred out of an array. Transaction performance measures how many I/O operations per second an array can perform. Redundancy defines an array’s ability to tolerate disk failures (i.e., the more disk failures it can tolerate, the higher the array’s redundancy.).
A brief review of the above RAID levels are given below:
(1) RAID 0 has no redundancy and is sometimes nicknamed JBOD, for ‘just a bunch of disks”,although the data may be striped across the disks in the array.
(2) RAID 3 makes use of a parallel access technique in which all member disks of the array participate in the execution of every I/O request, with a single parity disk and data being bit-wise striped (i.e., bit-interleaved parity).
(3) RAID 5 and RAID 6 make use of an ¡ndependent access technique in which each member disk of the array operates independently so that separate I/Os can be satisfied in parallel. The data are striped with a relatively large strip size in RAID 5 & 6. While RAID 5 can tolerate one disk failure, RAID 6 can tolerate two simultaneous disk failures.
(4) RAID 10 is a result of organizing mirrored pairs of disks, each pair being a RAID 1, into a RAID O (e.g., a 10-drive RAID 10 is an array of 5 RAID Is, with the data striped or distributed across the 5).
Please provide your brief justifications for your ranking in the space below.
RAID level
Storage Density
Bandwidth Performance
Transaction Performance
Redundancy
(reliability)
0
1(1st)
1(1st)
3
1(1st)
5
6
10
1(1st)
Explanation / Answer
a) Common characteristics of RAID levels:
1)RAID can be defined as a set of physical drives where it is integrated as a single logical drive by OS.Striping is the process of distributing data across physical drives using an array scheme.
2) RAID are interleaved
3) Data is distributed using round robin technique
b)
RAID level storage density bandwidth performance Transaction performance redundancy
0 1(st) 2(nd) 1(st) 3(rd)
3 2(nd) 1(st) 3(rd) 1(st)
5 1(ST) 2(st) 1(st) 2(nd)
6 1(st) 2(st) 1(st) 2(nd)
10 2(nd) 1(st) 3(rd) 1(st)
RAID 0 has good storage density and transaction performance so it is given as 1(st) but when coming to redundancy it has no redundancy so it is given as 3(rd) and performance of bandwidth is relatively high so it is given as 2(nd).
RAID 3 has better bandwidth performance and redundancy and trnasaction performance is very low so it is given as 3(rd) rank
RAID 5 and RAID 6 can tolerate failures so its transaction capability is very high and the storage is also very high so it is 1(st) and have minimal redundancy
RAID 10 comes from organising the disks so it is distributed and it have good bandwidth performance and redundancy and transaction performance is very low.