Understanding Operating Systems

1. Imagine that you are the manager of a small business computing center. List at least three techniques that you would use to convince a busy, reluctant night operator to perform regular backups. Explain the best and worst possible technique to assure your success.

2. Given multi-network access, it’s not unusual for users to have multiple user identifications and passwords. How would you manage these multi-password situations? Describe both the advantages and disadvantages of your solution.

3. Review the system with one CPU and four drives below:

• CPU W = 4 ms (the average time to execute 1,000 instructions)

• Drive A = 45 ms (average data access speed)

• Drive B = 3 ms (average data access speed)

• Drive C = 17 ms (average data access speed)

• Drive D = 10 ms (average data access speed)

Calculate I/O access speed using this CPU and each of the four disk drives as they evaluate the following track requests in this order: 0, 31, 20, 15, 20, 31, 15. Then, in each case, calculate the access speeds after the track requests are reordered and rank the four disk drives before and after reordering.