| With cloud computing becoming more and more popular, the need for obtaining a good multitenant systems is increasing. This thesis present a variation of the CFQ I/O scheduler that will provide fair throughput allocation when multiple processes or users try to access different sections of a hard disk drive. Because of the circular shape of the disks inside hard disk drive and the mechanics used to read the disks, the hard disk drives contain an embedded access unfairness.;The CFQ I/O scheduler, a common scheduler that can be found in many Linux distributions, fails to circumvent this unfairness and, under competition, the accesses performed on the outer part of the disks receive significantly better throughput the the accesses on the inner part of the disks.;This thesis report contains the background needed to motivate this thesis as well as the measurements that prove that there is an unfairness that the current CFQ I/O scheduler fails to solve. Once the importance of this thesis is justified and the status of the current CFQ I/O scheduler proved, this thesis will describe a the algorithm used to end with the embedded unfairness and show the measurements of the new, modified, scheduler proving that this unfairness has been minimized. |
