CSE451
Homework #5
Due Monday, March 3rd


1) The block is the minimum unit of file system allocation and I/O. A typical block size if 4 KB. Given this, how is it possible for the read() system call to return a single byte?

char buffer[1]; // one byte buffer
read (fileDescriptor,buffer,1);


2)  What is the largest possible file given a UNIX-like file system with the following characteristics. The i-node contains 12 direct pointers, 1 indirect block pointer, 1 doubly indirect block pointer, and 1 triply indirect block pointer. Block are 1 KB, and each block pointer is 4 bytes.


3) Files that reside on  outer cylinder groups can yield better
throughput than files on inner cylinder groups.  Why?


4) Describe the sequence of disk accesses that are required to read the following file: 

/homes/andrew/super-secret/final-solution.txt

You should make the following assumptions.  First, all caches are initially empty.  Second, once an item is referenced, it is cached forever.  Third, all directories are small.  Fourth, the solution file itself is small (i.e., fits in one block).  Finally, the file final-solution.txt is a hard link to the following file:

/homes/koishi/fs.txt


5) Repeat problem 4, except with a symbolic link instead of a hard link.

6. Silbershatz 12.2