Hard Drive Simulation By Steven Hyink Perry Kukura

Topics chosen File Management I/O Management

File Management & Hard Drive Management The file management arranges the data and gets it ready to be saved to the hard drive. It can arrange it in either a pile or an index. When the data is arranged, it is sent to the hard drive to be saved. It can be saved in one of four hard drive management policies.

File Management Program that receives files Stores them in an array Based on two of the file organization methods, Pile and Index

File Management GUI for program allows you to select Pile or Index organization method. You enter a String in the text box which will represent a file Click the ‘Save As’ button the file will be stored in the array in which management method you selected.

File Management The Pile method collects data in the order it arrives It’s purpose is to accumulate a mass of data and save it No structure Access is by exhaustive search

File Management The index method Uses multiple indexes for different key fields Could contain an exhaustive index that contains only one entry Could contain a partial index Index in program sorts by first character of file name

Searching and Deleting Searching is carried out from the file management GUI, and then is updated on the hard drive. When a file is searched for in the file management GUI, it is located on the hard drive, and is highlighted to show its position Deleting works the same, but once the file is located, it is deleted from the hard drive instead of highlighted.

Searching: Red: Empty Blue: Data Yellow: Data that was found

Deleting: The data that was highlighted is now gone, and has turned red.

I/O Hard Drive Management Implemented four hard drive management policies: FIFO, SSTF, SCAN, and C-SCAN. Implemented a Single Block-oriented Buffer. Both the hard drive and the buffer work in relation to the file management system.

First In First Out Basic loop that goes through the hard drive looking for open spots. When one is found, the data in the buffer is stored.

Shortest Service Time First Checks to see what is the shortest distance that it has to travel in order to put data into the hard drive.

SCAN Follows the direction that the head was moving. When it gets to the end of the drive, it travel back to where it started and continues saving data.

C-SCAN Follows the direction of the head, but when it reaches the end of the drive, it travels all the way to the beginning of the drive before it continues writing data.

Single Block-oriented Buffer The user adds a block of information to the buffer. While the buffer is putting data onto the hard drive, the user can be building the next block of data that is going to be put into the buffer.