1.
Formatting
http://www.thefreedictionary.com/formatting
 a. To divide (a disk) into marked sectors so that it may store data.
 b. To determine the arrangement of (data) for storage or display.
1.1.
Disk Formatting
http://en.wikipedia.org/wiki/Disk_formatting
Disk formatting is the process of
preparing a data storage device such as a
hard disk drive, solid-state drive, floppy disk
or USB flash drive for initial use. In some
cases, the formatting operation may also
create one or more new file systems. The
first part of the formatting process that
performs basic medium preparation is often
referred to as "low-level formatting".[1]
Partitioning is the common term for the
second part of the process, making the data
storage device visible to an operating
system.[1] The third part of the process, usually termed "high-level formatting" most
often refers to the process of generating a new file system.[1] In some operating
systems all or parts of these three processes can be combined or repeated at different
levels[NB 1] and the term "format" is understood to mean an operation in which a new
disk medium is fully prepared to store files. Illustrated to the right are the prompts
and diagnostics printed by MS-DOS's FORMAT.COM utility as a hard drive is being
formatted.
As a general rule,[NB 2] formatting a disk leaves most if not all existing data on
the disk medium; some or most of which might be recoverable with special tools. [4]
Special tools can remove user data by a single overwrite of all files and free space.[5]
1.1.1.
History
A block, a contiguous number of bytes, is the minimum unit of storage
that is read from and written to a disk by a disk driver. The earliest disk
drives had fixed block sizes (e.g. the IBM 350 disk storage unit (of the late
1950s) block size was 100 6 bit characters) but starting with the 1301[6] IBM
marketed subsystems that featured variable block sizes: a particular track
could have blocks of different sizes. The disk subsystems on the IBM
System/360 expanded this concept in the form of Count Key Data (CKD) and
later Extended Count Key Data (ECKD); however the use of variable block
size in HDDs fell out of use in the 1990s; one of the last HDDs to support
variable block size was the IBM 3390 Model 9, announced May 1993[7].
Modern hard disk drives, such as Serial attached SCSI (SAS)[8] and
Serial ATA (SATA)[9] drives, appear at their interfaces as a contiguous set of
fixed-size blocks; for many years 512 bytes long but beginning in 2009 and
accelerating through 2011, all major hard disk drive manufacturers began
releasing hard disk drive platforms using the Advanced Format of 4096 byte
logical blocks.[10][11]
Floppy disks generally only used fixed block sizes but these sizes were
a function of the host's OS and its interaction with its controller so that a
particular type of media (e.g., 5¼-inch DSDD) would have different block
sizes depending upon the host OS and controller.
Optical disks generally only use fixed block sizes.
1.1.2.
Disk Formatting Process
Formatting a disk for use by an operating system and its applications
typically involves three different processes.[NB 3]
1.1.2.1.
1.1.2.2.
1.1.2.3.
1.1.3.
Low-Level Formatting
Low-level formatting (i.e., closest to the hardware) marks
the surfaces of the disks with markers indicating the start of a
recording block (typically today called sector markers) and other
information like block CRC to be used later, in normal operations,
by the disk controller to read or write data. This is intended to be
the permanent foundation of the disk, and is often completed at
the factory.
Partitioning
Partitioning divides a disk into one or more regions, writing
data structures to the disk to indicate the beginning and end of the
regions. This level of formatting often includes checking for
defective tracks or defective sectors.
High-Level Formatting
High-level formatting creates the file system format within
a disk partition or a logical volume. This formatting includes the
data structures used by the OS to identify the logical drive or
partition's contents). This may occur during operating system
installation, or when adding a new disk. Disk and distributed file
system may specify an optional boot block, and/or various volume
and directory information for the operating system.
Low-Level Formatting Of Floppy Disks
The low-level format of floppy disks (and early hard disks) is
performed by the disk drive's controller.
Consider a standard 1.44 MB floppy disk. Low-level formatting of the
floppy disk, normally writes 18 sectors of 512 bytes to each of 160 tracks (80
on each side) of the floppy disk, providing 1,474,560 bytes of storage on the
disk.
Physical sectors are actually larger than 512 bytes, as in addition to
the 512 byte data field they include a sector identifier field, CRC bytes (in
some cases error correction bytes) and gaps between the fields. These
additional bytes are not normally included in the quoted figure for overall
storage capacity of the disk.
Different low-level formats can be used on the same media; for
example, large records can be used to cut down on inter-record gap size.
Several freeware, shareware and free software programs (e.g.
GParted, FDFORMAT, NFORMAT and 2M) allowed considerably more control
over formatting, allowing the formatting of high-density 3.5" disks with a
capacity up to 2 MB.
Techniques used include:
 head/track sector skew (moving the sector numbering forward at side
change and track stepping to reduce mechanical delay),
 interleaving sectors (to boost throughput by organizing the sectors on the
track),
 increasing the number of sectors per track (while a normal 1.44 MB format
uses 18 sectors per track, it is possible to increase this to a maximum of 21),
and
 increasing the number of tracks (most drives could tolerate extension to 82
tracks: though some could handle more, others could jam).
Linux supports a variety of sector sizes, and DOS and Windows
support a large-record-size DMF-formatted floppy format.[citation needed]
1.1.4.
Low-Level Formatting (LLF) Of Hard Disks
Hard disk drives prior to the 1990s
typically had a separate disk controller that
defined how data was encoded on the media.
With the media, the drive and/or the controller
possibly procured from separate vendors, low
level formatting was a potential user activity.
Separate procurement also had the potential of
incompatibility
between
the
separate
components such that the subsystem would
not reliably store data.[12]
User instigated low-level formatting (LLF) of hard disk drives was
common for minicomputer and personal computer systems until the 1990s.
IBM and other mainframe system vendors typically supplied their hard disk
drives (or media in the case of removable media HDDs) with a low-level
format. Typically this involved subdividing each track on the disk into one or
more blocks which would contain the user data and associated control
information. Different computers used different block sizes and IBM notably
used variable block sizes but the popularity of the IBM PC caused the industry
to adopt a standard of 512 user data bytes per block by the middle 1980s.
Depending upon the system, low-level formatting was generally done
by an operating system system utility. IBM compatible PCs used the BIOS,
which is invoked using the MS-DOS debug program, to transfer control to a
routine hidden at different addresses in different BIOSes.[13]
1.1.5.
Transition away from LLF
Starting in the late 1980s, driven by the volume of IBM compatible
PCs, HDDs became routinely available pre-formatted with a compatible lowlevel format. At the same time, the industry moved from historical (dumb) bit
serial interfaces to modern (intelligent) bit serial interfaces and Word serial
interfaces wherein the low level format was performed at the factory.
Today, an end-user, in most cases, should never perform a low-level
formatting of an IDE or ATA hard drive, and in fact it is often not possible to
do so on modern hard drives because the formatting is done on a servowriter
before the disk is assembled into a drive in the factory.[14][15]
1.1.6.
Disk Reinitialization
While it is generally impossible to perform a complete LLF on most
modern hard drives (since the mid-1990s) outside the factory,[16] the term
"low-level format" is still used for what could be called the reinitialization of a
hard drive to its factory configuration (and even these terms may be
misunderstood).
The present ambiguity in the term low-level format seems to be due to
both inconsistent documentation on web sites and the belief by many users
that any process below a high-level (file system) format must be called a lowlevel format. Since much of the low level formatting process can today only be
performed at the factory, various drive manufacturers describe
reinitialization software as LLF utilities on their web sites. Since users
generally have no way to determine the difference between a complete LLF
and reinitialization (they simply observe running the software results in a
hard disk that must be high-level formatted), both the misinformed user and
mixed signals from various drive manufacturers have perpetuated this error.
Note: Whatever possible misuse of such terms may exist (search hard drive
manufacturers' web sites for all these terms), many sites do make such
reinitialization utilities available (possibly as bootable floppy diskette or CD
image files), to both overwrite every byte and check for damaged sectors on
the hard disk.
Reinitialization should include identifying (and sparing out if possible)
any sectors which cannot be written to and read back from the drive,
correctly. The term has, however, been used by some to refer to only a
portion of that process, in which every sector of the drive is written to;
usually by writing a specific value to every addressable location on the disk.
Traditionally, the physical sectors were initialized with a filler value of
0xF6 as per the INT 1Eh's Disk Parameter Table (DPT) during format on IBM
compatible machines. This value is also used on the Atari Portfolio. 8-inch
CP/M floppies typically came pre-formatted with a value of 0xE5,[17] and by
way of Digital Research this value was also used on Atari ST and some
Amstrad formatted floppies.[NB 4] Amstrad otherwise used 0xF4 as a format
filler value. Some modern formatters wipe hard disks with a value of 0x00
instead, sometimes also called zero-filling, whereas a value of 0xFF is used on
flash disks to reduce wear. The latter value is typically also the default value
used on ROM disks (which cannot be reformatted). (Some advanced
formatting tools allow to configure the format filler byte.[NB 5])
One popular method for performing only the zero-fill operation on a
hard disk is by writing zero-value bytes to the drive using the Unix dd utility
with the /dev/zero stream as the input file and the drive itself or a specific
partition as the output file.[18] This command may take many hours to
complete, and can erase all files and file systems.
Another method for SCSI disks may use the sg_format[19] command to
issue a low level SCSI Format Unit Command.
Overwriting the drive with a zero-fill-command is not necessarily a
secure method of erasing sensitive data, or of preparing a drive for use with
an encrypted filesystem.[20]
1.1.7.
Partitioning
Main article: Disk partitioning
Partitioning is the process of writing information into blocks of a
storage device or medium that allows access by an operating system. Some
operating systems allow the device (or its medium) to appear as multiple
devices; i.e. partitioned into multiple devices.
On MS-DOS, Microsoft Windows, and UNIX-based operating systems
(such as BSD, Linux and Mac OS X) this is normally done with a partition
editor, such as fdisk, GNU Parted, and Disk Utility. These operating systems
support multiple partitions.
In current IBM mainframe OSs derived from OS/360 and DOS/360,
such as z/OS and z/VSE, this is done by the INIT command of the ICKDSF
utility.[21] These OSs support only a single partition per device, called a
volume. The ICKDSF functions include creating a volume label and writing a
Record 0 on every track.
Floppy disks are not partitioned; however depending upon the OS
they may require volume information in order to be accessed by the OS.
Partition editors and ICKDSF today do not handle low level functions
for HDDs and optical disk drives such as writing timing marks, and they
cannot reinitialize a modern disk that has been degaussed or otherwise lost
the factory formatting.
1.1.8.
High-Level Formatting
High-level formatting is the process of setting up an empty file system
on a disk partition or logical volume and, for PCs, installing a boot sector. This
is a fast operation, and is sometimes referred to as quick formatting.
The entire logical drive or partition may optionally be scanned for
defects, which may take considerable time.
In the case of floppy disks, both high- and low-level formatting are
customarily performed in one pass by the disk formatting software. 8-inch
floppies typically came low-level formatted and were filled with a format
filler value of 0xE5.[17][NB 4] Since the 1990s, most 5.25-inch and 3.5-inch
floppies have been shipped pre-formatted from the factory as DOS FAT12
floppies.
In current IBM mainframe operating systems derived from OS/360 or
DOS/360, this may be done as part of allocating a file, by a utility specific to
the file system or, in some older access methods, on the fly as new data are
written.
1.1.9.
Host protected area
Main article: Host protected area
The host protected area, sometimes referred to as hidden protected
area, is an area of a hard drive that is high level formatted so that the area is
not normally visible to its operating system (OS).
1.1.10.
Reformatting
Reformatting is a high-level formatting performed on a functioning
disk drive to free the contents of its medium. Reformatting is unique to each
operating system because what actually is done to existing data varies by OS.
The most important aspect of the process is that it frees disk space for use by
other data. To actually "erase" everything requires overwriting each block of
data on the medium; something that is not done by many PC high-level
formatting utilities.
Reformatting often carries the implication that the operating system
and all other software will be reinstalled after the format is complete. Rather
than fixing an installation suffering from malfunction or security
compromise, it is sometimes judged easier to simply reformat everything and
start from scratch. Various colloquialism exist for this process, such as "wipe
and reload", "nuke and pave", "reimage", etc.
1.1.11.
Formatting
1.1.11.1. DOS, OS/2 and Windows
format command: Under MS-DOS, PC-DOS, OS/2 and
Microsoft Windows, disk formatting can be performed by the
format command. The format program usually asks for
confirmation beforehand to prevent accidental removal of data,
but some versions of DOS have an undocumented /AUTOTEST
option; if used, the usual confirmation is skipped and the format
begins right away. The WM/FormatC macro virus uses this
command to format drive C: as soon as a document is opened.
Unconditional format: There is also the undocumented /U
parameter that performs an unconditional format which under
most circumstances overwrites the entire partition,[22] preventing
the recovery of data through software. Note however that the /U
switch only works reliably with floppy diskettes (see image to the
right). Technically because unless /Q is used, floppies are always
low level formatted in addition to high-level formatted. Under
certain circumstances with hard drive partitions, however, the /U
switch merely prevents the creation of unformat information in
the partition to be formatted while otherwise leaving the
partition's contents entirely intact (still on disk but marked
deleted). In such cases, the user's data remain ripe for recovery
with specialist tools such as EnCase or disk editors. Reliance upon
/U for secure overwriting of hard drive partitions is therefore
inadvisable, and purpose-built tools such as DBAN should be
considered instead.
Overwriting: In Windows Vista and upwards the non-quick
format will overwrite as it goes. Not the case in Windows XP and
below.[23]
OS/2: Under OS/2, if you use the /L parameter, which
specifies a long format, then format will overwrite the entire
partition or logical drive. Doing so enhances the ability of CHKDSK
to recover files.
1.1.11.2. Unix-like operating systems
High-level formatting of disks on these systems is
traditionally done using the mkfs command. On Linux (and
potentially other systems as well) mkfs is typically a wrapper
around filesystem-specific commands which have the name
mkfs.fsname, where fsname is the name of the filesystem with
which to format the disk.[24] Some filesystems which are not
supported by certain implementations of mkfs have their own
manipulation tools; for example Ntfsprogs provides a format utility
for the NTFS filesystem.
Some Unix and Unix-like operating systems have higherlevel formatting tools, usually for the purpose of making disk
formatting easier and/or allowing the user to partition the disk
with the same tool. Examples include GNU Parted (and its various
GUI frontends such as GParted and the KDE Partition Manager)
and the Disk Utility application on Mac OS X.
1.1.12.
Recovery of data from a formatted disk
As in file deletion by the operating system, data on a disk are not fully
erased during every[25] high-level format. Instead, the area on the disk
containing the data is merely marked as available, and retains the old data
until it is overwritten. If the disk is formatted with a different file system than
the one which previously existed on the partition, some data may be
overwritten that wouldn't be if the same file system had been used. However,
under some file systems (e.g., NTFS, but not FAT), the file indexes (such as
$MFTs under NTFS, inodes under ext2/3, etc.) may not be written to the
same exact locations. And if the partition size is increased, even FAT file
systems will overwrite more data at the beginning of that new partition.
From the perspective of preventing the recovery of sensitive data
through recovery tools, the data must either be completely overwritten
(every sector) with random data before the format, or the format program
itself must perform this overwriting, as the DOS FORMAT command did with
floppy diskettes, filling every data sector with the format filler byte value
(typically 0xF6).
However there are applications and tools, especially used in forensic
information technology, that can recover data that has been conventionally
erased. In order to avoid the recovery of sensitive data, governmental
organization or big companies use information destruction methods like the
Gutmann method.[26] For average users there are also special applications
that can perform complete data destruction by overwriting previous
information. Although there are applications that perform multiple writes a
single write is generally all that is needed on modern hard disk drives.
Create and format a hard disk partition
You must be logged on as an administrator to perform these steps.
To create a partition or volume (the two terms are often used interchangeably) on a hard disk,
there must be either unallocated (empty) space on the hard disk or free space within an extended
partition on the hard disk.
If there is no unallocated space, you can create some by shrinking an existing partition, deleting a
partition, or by using a third-party partitioning program. For more information, see
Can I repartition my hard disk? For more information about reformatting a hard disk, see the
"What is reformatting?" section below.
To create and format a partition (volume)
When you create partitions on a basic disk using Disk Management, the first three volumes you
create will be formatted as primary partitions. Beginning with the fourth volume, each volume will
be configured as a logical drive within an extended partition. For more information, see
What are partitions and logical drives?
1.
2.
3.
4.
5.
6.
7.
8.
Open Computer Management by clicking the Start button , clicking Control Panel,
clicking System and Maintenance, clicking Administrative Tools, and then doubleclicking Computer Management. If you are prompted for an administrator password or
confirmation, type the password or provide confirmation.
In the Navigation pane, under Storage, click Disk Management.
Right-click an unallocated region on your hard disk, and then click New Simple Volume.
In the New Simple Volume Wizard, click Next.
Type the size of the volume you want to create in megabytes (MB) or accept the maximum
default size, and then clickNext.
Accept the default drive letter or choose a different drive letter to identify the partition, and
then click Next.
In the Format Partition dialog box, do one of the following:

If you don't want to format the volume right now, click Do not format this volume,
and then click Next.

To format the volume with the default settings, click Next.
Review your choices, and then click Finish.
To format an existing partition (volume)



1.
2.
3.
4.
Warning
Formatting a volume will destroy any data on the partition. Be sure to make backups of any
data you want to save before you begin.
You cannot format a disk or partition that is currently in use, including the partition that
contains Windows.
Quick format is a formatting option that creates a new file table but does not fully
overwrite or erase the volume. A quick format is much faster than a normal format, which
fully erases any existing data on the volume.
Open Computer Management by clicking the Start button , clicking Control Panel,
clicking System and Maintenance, clicking Administrative Tools, and then doubleclicking Computer Management. If you are prompted for an administrator password or
confirmation, type the password or provide confirmation.
In the Navigation pane, under Storage, click Disk Management.
Right-click the volume that you want to format, and then click Format.
To format the volume with the default settings, in the Format dialog box, click OK, and then
click OK again.
What is reformatting?
Reformatting refers to formatting a hard disk or partition that already has been formatted or that
contains data on it. Reformatting a disk deletes all of the data on the disk.
In the past, reformatting a hard disk and reinstalling Windows was sometimes recommended as a
method for fixing a serious computer problem. Reformatting would fix the problem at the expense
of deleting everything on the computer. You would then have to reinstall your programs by using
the original installation files or discs, and then restore all of your personal files, such as documents,
music, and pictures, from backups that you had made beforehand.
Today, this version of Windows offers a number of recovery options that are less drastic and which
provide a better place to start fixing your computer problems. For more information, search
Windows Help and Support for "system recovery options." Reformatting and reinstalling should be
considered as a last resort that is only performed after all other recovery or diagnostic options
have proved unsuccessful.
You cannot reformat a disk or partition that is currently in use, including the partition that
contains Windows. This is a safety feature so that you cannot delete Windows by accident. To
reformat your computer's hard disk and reinstall Windows, restart your computer using the
Windows installation disc (this is commonly known as booting from the installation disc). During
the Setup process, you can repartition and reformat your hard disk and then reinstall Windows.
The process will erase your files and programs, so be sure to make backups of your data and
program files before you begin. For more information, search Windows Help and Support for
"installing and reinstalling Windows."