Since a boot manager usually supports multiple operating systems on one
computer and even one partition, it has to perform some preparatory actions
(create the boot context) before booting an operating system.
Partition. An independent area on a hard disk where a file system can be lo-
cated. A partition can be either primary or logical, depending on its position
in the partition structure. One of the primary partitions of a hard disk may be
active. A partition has the following attributes: type, beginning and size. Be-
sides, some partition managing software and boot managers allow hiding
partitions. Information about partitions is stored in the partition table.
Partitioning. The process of creating the logical structure on a hard disk. Par-
titioning is usually done with programs like FDISK. Disk Administrator com-
pletely replaces FDISK where functionality is concerned and allows perform-
ing many more useful operations.
Partition structure. All the partitions on a hard disk make a tree with the root
in the MBR partition table. Many operating systems and programs assume
that any partition table but MBR may contain not more than one partition en-
try and one table entry, and it simplifies the partition structure greatly – all
the logical partitions form one chain.
Partition table. It is the table that contains the information about partitions
and links to other partition tables. A partition table cannot have more than
four entries. Main partition table is located in the hard disk MBR, and the
other partition tables are called extended. Partition tables are usually stored
in the first sector of a cylinder.
Physical disk. A disk that is physically a separate device. Thus, floppy disks,
hard disks, CD-ROMs are physical disks.
Primary partition. The partition, information about which is contained in the
MBR partition table. Majority of operating systems can be booted only from
the primary partition of the first hard disk, but the number of primary parti-
tions is limited.
Root folder. The folder where the folder tree of a file system begins. Starting
from the root folder one can uniquely describe the file position on the folder
tree by sequentially naming all the intermediate nested folders, e.g.:
\WINDOWS\SYSTEM\VMM32.VXD. Here the WINDOWS folder is a subfolder
of the root folder, SYSTEM folder – of the WINDOWS folder, and the
VMM32.VXD file is located in the SYSTEM folder.
Sector. It is the minimal information unit on a disk that is transferred in sin-
gle read or write operation. Usually a sector is 512 bytes in size. A sector on
a disk can be addressed two ways: via the absolute number (see absolute
sector) or via cylinder, head and sector number on a track.
Copyright © SWsoft, 2000–2002
79
