ST: Unix Systems Administration Midterm

Spring 1995

• This midterm is due on Monday, March 20, 1995 at 11:59 pm.
• It may either be submitted electronically or on paper.
• Electronic submissions must conform to my Assignment Submission Guidelines.
• Paper submissions must be typed and must be submitted by the end of class on the 20th.

5 pts.

Provide all information (code, config files,resources, ...) necessary to implement a system which maintains a filesystem where the age of a core file never exceeds 5 days.

10 pts.

What are the legal forms for the "From: " line in a mail header? Justify your answer and give examples of all legal forms.

6 pts.

Under Sunos 4.1.? (Running on Nimitz).

• Where and how is the hostname set?
• Where and how is the network address set?
• Where should local daemons be started?

8 pts.

How many passwords are possible under HP-UX 9.? ? Assume you have a 100MIPS hp, and that you know the encrypted password, how long would it take to discover the un-encrypted password using the brute force method outlined below? State and justify any additional assumptions you make in solving this question.

         for each password between first_possible and last_possible
	    if (crypt(passwd) == encrypted_password) {
	       print "Found it"
	       exit
	    }

6 pts.

The following, from your text book (page 92), is describing default startup files. Please defend it.

      However, don't confuse users by "protecting"
      them from UNIX; entries such as:
	   alias dir ls -l
	   alias rm rm -i
      are considered poor form.

5 pts.

What problems can shared accounts cause?

5 pts.

What are the advantages and disadvantages of caching in a distributed database such as the one used for DNS? How are the disadvantages addressed in bind?

5 pts.

Write a utility which will unify /etc/passwd and /.secure/etc/passwd on an hp running HP-UX to a single standard password file. You may test this program on oslab.osnet.