Acronis os selector 8.0 User Manual
2.2
Hard Disk Formatting
A computer needs to have access to the necessary information at any time,
but even the smallest of hard disks can hold millions and millions of bits. So
how does a computer know where to look for the data required or where to
store the new data? Dividing the disks into small easily identifiable parts
solves this problem. This allows the computer to easily find the needed data.
The process of creation of such parts is called formatting. There are two
levels of formatting:
but even the smallest of hard disks can hold millions and millions of bits. So
how does a computer know where to look for the data required or where to
store the new data? Dividing the disks into small easily identifiable parts
solves this problem. This allows the computer to easily find the needed data.
The process of creation of such parts is called formatting. There are two
levels of formatting:
• physical formatting (or low-level formatting),
• logical formatting.
• logical formatting.
2.2.1 Physical
Formatting
Physical formatting of a hard disk must be performed first. Usually users do
not have to worry about this, since the manufacturer usually provides low-
level formatting. Physical formatting divides the surface of the magnetic
platters into tracks and sectors.
not have to worry about this, since the manufacturer usually provides low-
level formatting. Physical formatting divides the surface of the magnetic
platters into tracks and sectors.
• Tracks are concentric circles that are drawn on magnetic surfaces by the
magnetic heads. The tracks are assigned numbers from zero and up
center wards.
center wards.
• Tracks in their turn are divided into small areas that are called sectors
and contain a fixed amount of data. Usual sector size is 512 bytes (1
byte is equal to 8 bits).
byte is equal to 8 bits).
• All tracks that can be accessed without moving the read/write heads
form a cylinder. Track number and cylinder number are all the same.
Access to data inside one cylinder is much faster than re-positioning of
heads from one cylinder to another.
Access to data inside one cylinder is much faster than re-positioning of
heads from one cylinder to another.
Over time the magnetic surface gradually loses its properties and there
appear areas where data storage becomes impossible. Sectors that fall into
these areas are called bad. Fortunately the quality of modern hard disks is
such that they usually become outdated before failing. Most modern hard
disks are also able to substitute bad sectors with good ones from a special
reserve. But if bad sectors appear, they should be software treated, for
example by marking them so that they are not used.
appear areas where data storage becomes impossible. Sectors that fall into
these areas are called bad. Fortunately the quality of modern hard disks is
such that they usually become outdated before failing. Most modern hard
disks are also able to substitute bad sectors with good ones from a special
reserve. But if bad sectors appear, they should be software treated, for
example by marking them so that they are not used.
2.2.2 Logical
Formatting
A physically formatted disk also must be logically formatted. Logical
formatting means that a file system is created on the disk so that files can be
written to it or read from it. Different operating systems (OS) use different
file systems, so the way the disk should be formatted depends on the OS you
want to install.
formatting means that a file system is created on the disk so that files can be
written to it or read from it. Different operating systems (OS) use different
file systems, so the way the disk should be formatted depends on the OS you
want to install.
18
Chapter 2 : Basic Information