Question

Question about Hard Disks

1. For Redundant Arrays of Inexpensive Disks, which of the following two has more reliability? The Level 0 + 1 (Striping + Mirroring) or Level 1 + 0 (Mirroring + Striping)? Why?

2. Why does the Elevator have better performance than Shortest Seek Time First algorithm for a heavy load? (Elevator is also called the SCAN or C-SCAN)

3. Do accesses to sectors in outer tracks require less time compared to accesses sectors to inner tracks? Why or why not?

Answer 1

In case of any queries, please revert back.

1. Joining two storage levels makes RAID 10 quick and versatile simultaneously. On the off chance that you need equipment level insurance for your data and quicker storage execution, RAID 10 is a straightforward, generally reasonable fix. RAID 10 is secure on the grounds that reflecting copies every one of your data. It's quick on the grounds that the data is striped over various disks; pieces of data can be perused and kept in touch with various disks all the while. Since the expenses of disks are diminishing, including steady storage space is presently more affordable than any time in recent memory, regardless of whether you are adding extra disks to help your RAID 10 cluster or supplanting the disk controller on your motherboard in the event that it doesn't bolster RAID 10.

2. Elevator calculation In this calculation, the head pointer begins from one finish of disk and moves towards the opposite end, serving all solicitations in the middle. Subsequent to arriving at the opposite end, the head turn around its course and go to the beginning stage. It at that point fulfills the rest of the solicitations, in same bearing as in the past. Dissimilar to SSTF, it can deal with demands just in one direction. Elevator calculation gives low change in normal holding up time and reaction time.   Whereas SSTF gives high difference in normal holding up time and reaction time. Elevator calculation will never make starvation any requests as compared to SSTF .Performance of C-SCAN is far superior than SSTF. Whereas SSTF slacks in execution.

3. The outer sectors have lower bit thickness than the inward ones, which is a wasteful utilization of the attractive surface. The arrangement is zone bit recording, wherein the disk is separated into zones, each enveloping few touching tracks. Each zone is then partitioned into sectors with the end goal that every sector has a comparable physical size. An outcome of zone bit recording is that adjoining peruses and composes are perceptibly quicker on outer tracks than on inward tracks, as more bits go under the head with every turn and this distinction can be 25% or more.