In Chapter 4 we go through the concept of file systems. As we understand, storing a file as a contiguous sequence of bytes could be problematic. Therefore, a common practice is to divide files int fixed-size blocks that need not be adjacent. So there are several things we need to pay attention. The first is the block size. The next question would be how to track of free blocks. This simulation asks you to create a file system of such. Here is what I would like you to do for the Memory Management Simulator:
Download, install and run the self-extracting ZIP archive (filesys.exe) into a folder you create. If you have any difficulty downloading this file, you may also download it directly from ontko.com.
Run the mkfs program in the format of: java mkfs file-name block-size blocks where:
file-name is the name of the backing file to create (e.g., filesys.dat).
Note that this is the name of a real file, not a file in simulator. This is the file that the simulator uses to simulate the disk device for the simulated file system. This may be any valid file name in your operating system environment.
block-size is the block size to be used for the file system (e.g., 256).
This should be a multiple of the index node (i-node) size (usually 64) and the directory entry size (usually 16).
Modern operating systems usually use a size of 1024, or 512 bytes. We use 128 or 256 byte block sizes in many of our examples so that you can quickly see what happens when directories grow beyond one block. This should be a decimal number not less than 64, but less than 32768.
blocks is the number of blocks to create in the file system(e.g., 40).
This number includes any blocks that may be used for the superblock, free list management, inodes, and data blocks.
We use a relatively small number here so that you can quickly see what happens if you run out of disk space. This can be any decimal number greater than 3, but not greater than 224 – 1 (the maximum number of blocks), although you may not have sufficient space to create a very large file.
Use mkfs to create a file system with a block size of 64 bytes and having a total of 8 blocks.
Create a screen shot of your program running and submit it along with brief answers to the following questions:
How many index nodes will fit in a block?
How many directory entries will fit in a block?
How many directories can you create before you fill up the file system?
General Instructions for Lab Assignments
Your lab assignment needs to be presented in a professional manner and include your name, course, the title of assignment, professor’s name, date, task, and include a list of sources used, if applicable. The Research and Library Tips page will help you properly cite sources using a consistent format, so that your academic integrity is not called into question. The final lab assignment must include answers that are clear and help to describe the changes made to the program and any rationale that helps to detail how you derived your answers. The evaluation of your submission will consider grasp of readings, depth of analysis, content organization, clarity of writing and vocabulary use.
Be sure to submit your lab assignment by the close of this module, I would prefer that it is attached as a .doc or .rtf formatted document.
