Howdy CS 4750 Class -- Here is the third homework assignment. Check the class schedule for the due date. I prefer that you just fill out the answers in a copy of this e-mail and send it to me by e-mail. Many of these problems can be answered well with just a sentence or two. Some require a bit of thought, and some extra wording. Use good judgement. That's a part of what I will be grading you on. Answers that offer inadequate information and/or aid to understanding will receive little credit, even if technically correct. Remember that the point of these exercises is for you to demonstrate that you have read and understood the material. Therefore always give the "textbook" answer (Nemeth or Vahalia, as the case may be) along with any individual opinions or answers that you want to put forward. -- john ////////////////////////////////////////////////// PART I: Homework #4 Problems for Nemeth Chapter 25: Printing and Imaging Chapter 15: Network Hardware Chapter 17: The Network File System Chapter 16: The Domain Name System ////////////////////////////////////////////////// /////////////////////////////////////////////////////////////// Questions on Chapter 25 of Nemeth -- Printing and Imaging /////////////////////////////////////////////////////////////// ----------------------------------------------------------------- 1. Under BSD printing, how does Nemeth suggest you might prevent users from printing binary files to line printers? ----------------------------------------------------------------- 2. Suppose that BSD style printing is already configured and working on host barnard, using a line printer (lp1) directly connected to barnard. You are the administrator of a linux host called zeppo, and you want to set things up so that zeppo can send jobs to barnard's lp1 to be printed. Zeppo also has BSD style printing. What do you have to do? ----------------------------------------------------------------- /////////////////////////////////////////////////////////////// Questions on Chapter 15 of Nemeth -- Network Hardware /////////////////////////////////////////////////////////////// ----------------------------------------------------------------- 3. What is the difference between a repeater and a bridge? ----------------------------------------------------------------- 4. Nemeth terms FDDI the disappointing LAN. Why? ----------------------------------------------------------------- 5. In essence, what is Nemeth's advice to those of us that are creating new networks, possibly in new buildings and new locations? ----------------------------------------------------------------- /////////////////////////////////////////////////////////////// Questions on Chapter 17 of Nemeth -- The Network File System /////////////////////////////////////////////////////////////// ----------------------------------------------------------------- 6. What is the purpose of nfsd? What does it do? On which type of system is it designed to be used: an nfs client, or an nfs server? ----------------------------------------------------------------- 7. When an NFS server receives a write-request from a client, the server is required to "push the write" to non-volatile storage before acknowledging the write to the client. The server is not allowed to merely do the write to a file buffer in volatile RAM. What is the reason for this requirement? ----------------------------------------------------------------- /////////////////////////////////////////////////////////////// Questions on Chapter 16 of Nemeth -- The Domain Name System /////////////////////////////////////////////////////////////// ----------------------------------------------------------------- 8. What is the actual difference between what a primary nameserver does and what a secondary nameserver does? ----------------------------------------------------------------- ///////////////////////////////////////////////////////////////// PART II: Homework #3 Problems for The Kernel (Vahalia) Book. Chapter 12: Kernel Memory Allocation Chapter 13: Virtual Memory Chapter 14: The SVR4 VM Architecture ///////////////////////////////////////////////////////////////// //////////////////////////////////////// Chapter 12 -- Kernel Memory Allocation //////////////////////////////////////// ----------------------------------------------------------------- Variant of Problem #7: Suppose that a buddy algorithm manages a 1024-byte area of memory with a minimum allocation size of 16 bytes. When an allocation is done, what is the maximum number of splits that the allocator might perform? When a buffer is freed, what is the maximum number of coalescings that the allocator might perform? Illustrate the worst case behavior of the simple buddy algorithm by using diagrams of the kind on page 384 (Figure 12-6). You must make a figure showing some initial configuration of the free lists. Then make any additional figures, as required, to show how a series of alternating allocate and release requests could cause the maximum number of splits and coalesces to happen every time one of the requests is serviced. ----------------------------------------------------------------- //////////////////////////////////////// Chapter 13 -- Virtual Memory //////////////////////////////////////// ----------------------------------------------------------------- Problem #15. What are the factors that limit the maximum amount of virtual address space a process may have? Why, if at all, is it important for a process to be thrifty in its use of virtual memory? ----------------------------------------------------------------- //////////////////////////////////////// Chapter 14 -- The SVR4 VM Architecture //////////////////////////////////////// ----------------------------------------------------------------- Problem #1. In what ways is mapped file access semantically different from access through read and write system calls? -----------------------------------------------------------------