Ch 3 Disks and Formatting

Instructor: Prof. Michael P. HarrisChapter 3

Answers to Discussion Questions Disks & Formatting

Chapter 3

Disks and Formatting

ANSWERS TO DISCUSSION QUESTIONS (pp. 120-121)

1.What purpose do disks serve?

Disks permanently store data and programs. They also allow programs and data to be transportable.

2.Why must you format a disk?

All disks must be formatted before they can be used. Every operating system has its specific way of laying out the structure of a disk to match its operating system. Formatting sets up tracks, sectors, clusters, etc., on the disk so that the OS can read and write data and programs to the disk. You may also reformat a used disk in order to reuse it, but all the old data that is on the disk will be lost.

3. Compare and contrast physical (low-level) formatting with logical (high-level) formatting of a disk.

Low-level or physical formatting prepares a disk for use by a computer by creating the physical structure of tracks and sectors. High-level or logical formatting builds the disk’s file structure so that the OS can use the disk.

Low-level formatting is done to identify each track and sector while high-level formatting is done so files can be stored and retrieved.

4.Define tracks, sectors, and clusters.

Tracks - The concentric circles on a disk that resembles the grooves on a record.

Sectors - Tracks are broken into numbered sectors on a disk.

Clusters - Consists of one or more adjacent sectors. It is the smallest unit that Windows/DOS will read from or write to.

5.What is the purpose and function of the boot record?

Every disk has a boot record. The boot record is created during the logical formatting of the disk and is located in the first portion of the disk. It contains information about the physical characteristics of the disk such as: the number of tracks per disk, the number of bytes per sector, the number of sectors per track, the version of the operating system, the size of the FAT, and the volume serial number.

If the disk is a bootable disk, it will have a bootstrap loader to load the operating system. If it is not a bootable disk, it will display the message that it is a non-system disk, when you try to boot from it.

6.Define FAT. How is it used on a disk?

FAT (File Allocation Table) is a map of every track and sector on the disk. It tells the OS where files are at on the disk. The FAT entries contain information about which clusters have data and which have bad sectors. If a file utilizes more than one cluster, the FAT links the clusters for that specified file. The FAT links the file by pointing to the next cluster that holds the data.

7.Compare and contrast FAT, FAT32, and NTFS.

The file allocation table (FAT) contains numbers that point to the clusters that make up a file. The computer uses these numbers to chain together a series of clusters to make a complete file. The FAT and the root directory comprise the architecture of the system.

FAT32 is a 32-bit FAT that is an enhancement of the FAT system. It supports drives sizes of up to a terabyte allowing larger disk support.

The NTFS file system, first introduced in Windows NT, is the preferred file system to FAT, VFAT, and FAT32. Besides offering enhanced performance needed for the much larger disk drives seen today, it also offers security management for files and folders on the machine. Other advantages include faster access to files and folders, better data recovery, and an ability to compress files that allows more data to be stored on a disk.

8.What is the purpose and function of the root directory in a FAT file system?

The root directory table contains information about each file on the disk and the FAT address of the starting cluster number of each file. File information includes filename, file extension, size of file in bytes, date and time file last modified, and file’s attributes. W2K uses unused areas in the table to handle long file names.

The FAT contains the map to where the data is located on the disk; this data is found through the use of pointers that point to the next cluster to where the file is stored. It includes an EOF (end-of-file) marker that indicates that a file has no more clusters. It will also mark any clusters that are bad so that they are not used to store data.

The root directory tells W2K what is on the disk, and the FAT tells W2K where the data is on the disk.

The information displayed by both Windows Explorer and My Computer comes from the root directory table.

9.How is space allocated to files in FAT? In NTFS?

Space is allocated to files in FAT by the operating system in clusters. The OS writes files to a disk in the first available cluster, and if possible, to adjacent or contiguous clusters. If adjacent clusters are already in use then the OS will skip to the next available space or noncontiguous cluster.

Instead of using FAT, NTFS uses a special file called the Master File Table (MFT) that tracks all the files and directories in a volume. The MFT is really a database that tracks all the files and directories in the system. Different than FAT, the data in the MFT file is considered just an attribute in the file and, if the amount of data is small enough, the entire file will fit in the MFT. If the data is too large to fit into the MFT record, NTFS will store it in cluster units called a run or an extent.

10.FORMAT can be a dangerous command. Explain.

FORMAT is a dangerous command because when a disk is formatted it erases all data from that disk. Generally this data is unrecoverable. Always be sure to have the correct disk in the drive when a disk is formatted.

11.What does the prompt on the screen represent?

The prompt displays the default drive and default directory.

12.Compare and contrast internal and external commands.

Internal commands are those that are always present in the computer until the computer is turned off. They are also called resident commands since they reside in the computer.

External commands are those commands that must be loaded from the disk each time they are used. They are called transient commands since they must be loaded each time that they are used.

13.What steps can you take when you see error messages?

When you see error messages it is the OS saying, "I don't understand what you want." Error commands are usually caused by an error in typing the name of the command, trying to run a program from the wrong drive or directory, or when the path is not correctly set. Check all of these when you see an error message.

14.What is a volume label?

The volume label is the electronic name that is given to a disk. It is displayed when the DIR and VOL commands are used. It is used to identify a disk.

15.When formatting a disk, the drive letter is a mandatory parameter. Why?

The disk drive letter is required when formatting a disk to help prevent accidentally formatting the wrong drive.

16.Give the syntax for the FORMAT command and explain each item.

The FORMAT command has many parameters, some of which are used more than others. The basic syntax for the FORMAT command is: FORMAT volume

Some of the more frequently used parameters are listed as follows:

Volume Specifies drive letter (followed by a colon), mount-point or volume name. Refers to drive to be formatted.

/V: labelSpecifies the volume label.

/QPerforms a quick format.

/F:sizeSpecifies size of floppy disk to format.

17.Explain the purpose and function of a quick format.

The /Q parameter does a quick reformat of an already formatted disk. It deletes the entries from the FAT and the root directory but leaves file areas untouched.

18.When using the FORMAT command, what is the purpose and function of the parameter /V?

The /V parameter specifies that you want to place an electronic label on the disk.

19.What is the purpose and function of the VOL command?

The internal VOL command allows you to view the volume label on any disk or check to see if there is a label. By using this label you can quickly see what is on disk without having to execute the directory command.

20.What is the purpose and function of the LABEL command?

The external LABEL command allows you to change the internal volume label without reformatting the disk.

21.When using the FORMAT command, when would you use the /Q parameter?

The /Q parameter is used when you simply want to erase all files from an already formatted disk. It works like the usual FORMAT command but skips the low-level formatting.

Carolyn Z. Gillay, Bette A. Peat, Windows XP Command Line