Acronis disk director suite 9.0 User Manual

Glossary

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Appendix C. Glossary

Absolute sector. All the sectors of a hard disk can be numbered sequentially,
starting with zero. Such numbered sectors are called absolute.

Active partition. One of the primary partitions of a hard disk is usually active.
Default MBR code tries to boot an operating system from the active partition of
the first hard disk. Letter assignment in Microsoft operating systems depends on
which partitions are active.

Bad cluster. A cluster that contains bad sectors. Such a cluster cannot store
information with possible corruption of the data.

Bad sector. A sector that cannot store the information written, for instance due
to defects or aging of the magnetic surface.

Booting is a procedure that is executed every time a computer is turned on or an
operating system finishes its work or when the reset button is pressed. Booting
consists of the following stages:

•  Hardware diagnostics
•  Memory check
•  Built-in BIOS initialization
•  Initialization of additional hardware components and their BIOSes (video, SCSI

etc.)

• Booting an operation system

If a boot manager is installed on a computer, it is booted instead of an operating
system. Then the boot manager boots the user-selected operating system itself.

Boot record. The initial part of a partition that contains code and data necessary
for booting an operating system. May consist of one or several sectors. The first
sector of a boot record must end with the boot sector signature (0AA55h).

Boot sector is the first sector of a disk or a partition that contains the initial code
for the operation system booting. The boot sector must end with the 0AA55h
signature.

Bootable disk is a disk from which an operating system may be booted. A
bootable disk must contain a boot sector of an operating system and the
necessary system and configuration files. The «bootable disk» term usually refers
to diskettes and CD-ROMs.