Alsoft DiskWarrior - 2.0 Instruction Manual
Basic Terms You Need To Know
Chapter 1: Introduction
15
Basic Terms You Need To Know
This section explains some terms and concepts that are used throughout this manual.
Application
An application is a tool your computer uses to manipulate information and perform a
useful function for you. Applications include such products as AppleWorks.
useful function for you. Applications include such products as AppleWorks.
Block
The physical surface of a disk is comprised of many 512 byte storage areas called
physical blocks. The larger the disk, the greater the number of physical blocks on the
disk. An allocation block is a group of one or more physical blocks treated as a single
storage area by the Mac OS. The older Mac OS Standard format, or HFS, can only keep
track of 65,535 allocation blocks per disk. Therefore, the larger the size of a disk, the
greater the number of physical blocks in each allocation block, so that the total
number of storage areas on the disk does not exceed the maximum of 65,535. The
newer Mac OS Extended format, or HFS Plus, can keep track of over 4 billion allocation
blocks per disk. HFS Plus uses allocation blocks sizes ranging from 0.5 KB to 4 KB. The
Macintosh filing system stores files by breaking them into allocation block-size pieces
and writing them into unused allocation blocks wherever they are available.
physical blocks. The larger the disk, the greater the number of physical blocks on the
disk. An allocation block is a group of one or more physical blocks treated as a single
storage area by the Mac OS. The older Mac OS Standard format, or HFS, can only keep
track of 65,535 allocation blocks per disk. Therefore, the larger the size of a disk, the
greater the number of physical blocks in each allocation block, so that the total
number of storage areas on the disk does not exceed the maximum of 65,535. The
newer Mac OS Extended format, or HFS Plus, can keep track of over 4 billion allocation
blocks per disk. HFS Plus uses allocation blocks sizes ranging from 0.5 KB to 4 KB. The
Macintosh filing system stores files by breaking them into allocation block-size pieces
and writing them into unused allocation blocks wherever they are available.
Directory
The directory of a disk is a group of allocation blocks set aside by the Mac OS to store
the number, name, location (which allocation blocks), and size of each file and folder
stored on the volume.
the number, name, location (which allocation blocks), and size of each file and folder
stored on the volume.
Directory Data
The directory data includes the information about the numbers, names, locations,
types, and sizes of files and folders saved on the disk.
types, and sizes of files and folders saved on the disk.
Directory Structure
The directory structure is how the directory data is organized within the directory. The
Mac OS uses the directory structure to quickly access the directory data. Its structure
is an indexed database, similar to that used by the Finder in the desktop database, as
well as by FileMaker with its databases.
Mac OS uses the directory structure to quickly access the directory data. Its structure
is an indexed database, similar to that used by the Finder in the desktop database, as
well as by FileMaker with its databases.
Disk
A disk is the medium on which information is stored. There are many types of disks
including floppy disks, hard disks (like the one that is probably inside your Mac OS
computer), and removable disks. A disk must be initialized before it can be used.
including floppy disks, hard disks (like the one that is probably inside your Mac OS
computer), and removable disks. A disk must be initialized before it can be used.
Document
A document is a type of file that you create with an application. Documents include the
information you enter, modify, view, or save to a disk.
information you enter, modify, view, or save to a disk.