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Table 1 I/O request submission order to the block layer

From: Host managed contention avoidance storage solutions for Big Data

Order

Request

LBA

Transfer size

Track no. (cylinder)

Read/write

Time to expire (ms)

1

B1

7125

40

71

W

Exp#1

2

A1

305

24

3

R

Exp#2

3

A2

340

24

3

R

Exp#3

4

A3

370

24

3

R

Exp#4

5

C1

1600

4

16

R

Exp#5

6

B2

7165

40

71, 72

W

50

7

B3

7205

40

72

W

53

8

A4

410

24

4

R

60

9

A5

440

24

4

R

65

10

A6

470

24

4

R

100

11

C2

1670

4

16

R

105

12

B4

7245

40

72

W

110

  1. \(A_n\), \(B_n\), \(C_n\) nth request of processes A, B, C submitted to the “request queue”, LBA starting logical block address (LBA) of the sorted “request” structure, Transfer size number of disk blocks required for data transfer, Track no. the track (or tracks) where the entire request spans, Read/write type of operation read ‘r’ or write ‘w’ performed by the request, Time to expire time left in milliseconds at system time ‘k’ for the request to expire as per the deadline determined by the Deadline Scheduling Algorithm, Exp#‘x’ Exp. denotes that the request has already expired and ‘x’ is the order in which it has expired