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