BMCloud: Minimizing Repair Bandwidth and Maintenance Cost in Cloud Storage

Algorithm 2

Algorithm enumeration recovery.

1: Requirements:

2:  Native chunks;

3:  Repair request;

4:  Main parameters (𝑛,𝑘,𝑠) in F-MSR code and E  Code;

5:  k stands for the number of fail strips

6: Step  1. Basic information collection

7: Step  2. Greedy repair

8:  (a): Scan failed strip 𝑆_𝑖 (1<𝑖<𝑘);

9:  (b): If 𝑆_𝑖can be recovered by a simple data-link

10:   then restore 𝑆_𝑖, go to Step  1.

11:   else 𝑖=𝑖+1;

12:  (c): List the equation set of the rest of the failed strips

13:   from the related data-links

14:  (d): If the equation set is soluble

15:    then restore all the failed strips

16:    else got Step  3.

17: Step  3. Functional Repair

18:  (a): Repair the whole node with F-MSR code;

19:  (b): Recalculate the related parity strip and update all

20:   the EMs on every cloud server;