Understanding Operating Systems Questions

Given that it takes 1.75 ms to travel from one track to the next of a hard

drive; that the arm is originally positioned at Track 15 moving toward the

low- numbered tracks; and that you are using the LOOK scheduling policy:

Compute the total seek time to satisfy the following requests—4, 40, 35, 11,

14, and 7. Assume all requests are initially present in the wait queue. (Ignore

rotational time and transfer time; just consider seek time.)

Describe how implementation of a RAID Level 2 system would be beneficial

to a university payroll system. In your own words, describe the disadvantages

of such a system, if any, in that environment, and if appropriate, suggest an

 alternative RAID system and explain your reasoning.

Imagine one real-life example of each: a multi-file volume and a multi- volume

file. Include a description of the media used for storage and a general description

of the data in the file.

The following is an access verification technique, listing several files and the

access allowed for a single user. Identify the control technique used here, and

for each, explain the type of access allowed.

 a. File_1 R-E-

 b. File_12 RWE-

 c. File_13 RW--

 d. File_14 –E-

Devise a way to compress the following list of last names using a lossless

 technique similar to that shown in Table 8.6 for repeated terms. Describe your

method and show the compressed list. Explain the characteristics that make

your technique lossless (and not lossy).

 McConnor, Nelson

 McDavid, Nelson

 McDavid, Patricia

 McDonald, Mary

 McDonald, Marie

 McDonnell, Mike