is either a bootable Acronis OS Selector CD-ROM or a diskette that can be
created by running Acronis OS Selector from any operating system that is
DOS-compatible on the direct drive access level.
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 what partitions are active. For details about active partitions see
8.3 «Setting an Active Partition».
Bad cluster. A cluster that contains bad sectors. Such cluster cannot store
useful information.
Bad sector. A sector that cannot store the information written, for instance
due to defects or aging of the magnetic surface.
BIOS extension. BIOSes that were released before 1994 can only support
hard disks that are less than 8 gigabytes. Extended hard disk management
functions were added to BIOSes to solve this problem, and now the
maximum supported hard disk capacity is 2
75
bytes.
Boot context. Before booting the selected operating system a boot manager
must create its boot context. Acronis OS Selector includes the following
components into the boot context:
• Boot sector;
• System files;
• Configuration files;
• System folders;
• Hidden partitions;
• Active partitions;
• LBA partition support flags.
Boot context is created in the following way:
• System and configuration files are copied from backups to their proper
places (usually it is the root folder of the operation system partition);
• System folders are moved to their proper places;
• Hidden partitions are set;
• Active partitions are set;
• If the LBA support flag is present, than all partition types are changed to
LBA;
• Boot sector is loaded and executed.
130 Appendix F. : Glossary
