FORMAT(8) Maintenance Commands and Procedures FORMAT(8)

NAME

format - disk partitioning and maintenance utility

SYNOPSIS

format [-f command-file] [-l log-file] [-x data-file]
[-d disk-name] [-t disk-type] [-p partition-name]
[-s] [-m] [-M] [-e] [disk-list]

DESCRIPTION

format enables you to format, label, repair, and analyze disks on
your system. Unlike previous disk maintenance programs, format runs
under SunOS. Because there are limitations to what can be done to the
system disk while the system is running, format is also supported
within the memory-resident system environment. For most applications,
however, running format under SunOS is the more convenient approach.


format first uses the disk list defined in data-file if the -x option
is used. format then checks for the FORMAT_PATH environment variable,
a colon-separated list of filenames and/or directories. In the case
of a directory, format searches for a file named format.dat in that
directory; a filename should be an absolute pathname, and is used
without change. format adds all disk and partition definitions in
each specified file to the working set. Multiple identical
definitions are silently ignored. If FORMAT_PATH is not set, the path
defaults to /etc/format.dat.


disk-list is a list of disks in the form c?t?d? or
/dev/rdsk/c?t?d?s?. With the latter form, shell wildcard
specifications are supported. For example, specifying /dev/rdsk/c2*
causes format to work on all drives connected to controller c2 only.
If no disk-list is specified, format lists all the disks present in
the system that can be administered by format.


Removable media devices are listed only when users execute format in
expert mode (option -e). This feature is provided for backward
compatibility. Use rmformat(1) for rewritable removable media
devices.

OPTIONS

The following options are supported:

-d disk-name
Specify which disk should be made current upon
entry into the program. The disk is specified by
its logical name (for instance, -d c0t1d0). This
can also be accomplished by specifying a single
disk in the disk list.


-e
Enable SCSI expert menu. Note this option is not
recommended for casual use.


-f command-file
Take command input from command-file rather than
the standard input. The file must contain
commands that appear just as they would if they
had been entered from the keyboard. With this
option, format does not issue continue? prompts;
there is no need to specify y(es) or n(o)
answers in the command-file. In non-interactive
mode, format does not initially expect the input
of a disk selection number. The user must
specify the current working disk with the -d
disk-name option when format is invoked, or
specify disk and the disk selection number in
the command-file.


-l log-file
Log a transcript of the format session to the
indicated log-file, including the standard
input, the standard output and the standard
error.


-m
Enable extended messages. Provides more detailed
information in the event of an error.


-M
Enable extended and diagnostic messages.
Provides extensive information on the state of a
SCSI device's mode pages, during formatting.


-p partition-name
Specify the partition table for the disk which
is current upon entry into the program. The
table is specified by its name as defined in the
data file. This option can be used only if a
disk is being made current, and its type is
either specified or available from the disk
label.


-s
Silent. Suppress all of the standard output.
Error messages are still displayed. This is
generally used in conjunction with the -f
option.


-t disk-type
Specify the type of disk which is current upon
entry into the program. A disk's type is
specified by name in the data file. This option
can only be used if a disk is being made current
as described above.


-x data-file
Use the list of disks contained in data-file.

USAGE

When you invoke format with no options or with the -e, -l, -m, -M, or
-s options, the program displays a numbered list of available disks
and prompts you to specify a disk by list number. If the machine has
more than 10 disks, press SPACE to see the next screenful of disks.


You can specify a disk by list number even if the disk is not
displayed in the current screenful. For example, if the current
screen shows disks 11-20, you can enter 25 to specify the twenty-
fifth disk on the list. If you enter a number for a disk that is not
currently displayed, format prompts you to verify your selection. If
you enter a number from the displayed list, format silently accepts
your selection.


After you specify a disk, format displays its main menu. This menu
enables you to perform the following tasks:

analyze
Run read, write, compare tests, and data purge. The data
purge function implements the National Computer Security
Center Guide to Understanding Data Remnance (NCSC-TG-025
version 2) Overwriting Algorithm. See NOTES.


backup
Search for backup labels.


cache
Enable, disable, and query the state of the write cache
and read cache. This menu item only appears when format
is invoked with the -e option, and is only supported on
SCSI devices.


current
Display the device name, the disk geometry, and the
pathname to the disk device.


defect
Retrieve and print defect lists. This option is
supported only on SCSI devices. IDE disks perform
automatic defect management. Upon using the defect
option on an IDE disk, you receive the message:

Controller does not support defect management
or disk supports automatic defect management.


disk
Choose the disk that will be used in subsequent
operations (known as the current disk.)


fdisk
Run the fdisk(8) program to create a fdisk partition for
Solaris software (x86 based systems only).


format
Format and verify the current disk. This option is
supported only on SCSI devices. IDE disks are pre-
formatted by the manufacturer. Upon using the format
option on an IDE disk, you receive the message:

Cannot format this drive. Please use your
manufacturer-supplied formatting utility.


inquiry
Display the vendor, product name, and revision level of
the current drive.


label
Write a new label to the current disk.


partition
Create and modify slices.


quit
Exit the format menu.


repair
Repair a specific block on the disk.


save
Save new disk and slice information.


type
Select (define) a disk type.


verify
Read and display labels. Print information such as the
number of cylinders, alternate cylinders, heads,
sectors, and the partition table.


volname
Label the disk with a new eight character volume name.

ENVIRONMENT VARIABLES

FORMAT_PATH
a colon-separated list of filenames and/or directories
of disk and partition definitions. If a directory is
specified, format searches for the file format.dat in
that directory.

FILES

/etc/format.dat
default data file

SEE ALSO

rmformat(1), sd(4D), format.dat(5), attributes(7), fmthard(8),
prtvtoc(8)


x86 Only
fdisk(8)

WARNINGS

When the format function is selected to format the Maxtor 207MB disk,
the following message displays:

Mode sense page(4) reports rpm value as 0, adjusting it to 3600


This is a drive bug that may also occur with older third party
drives. The above message is not an error; the drive will still
function correctly.


Cylinder 0 contains the partition table (disk label), which can be
overwritten if used in a raw disk partition by third party software.


format supports writing EFI-compliant disk labels in order to support
disks or LUNs with capacities greater than one terabyte. However,
care should be exercised since many software components, such as
filesystems and volume managers, are still restricted to capacities
of one terabyte or less. See the System Administration Guide: Basic
Administration for additional information.


By default, on an unlabeled disk, EFI labels will be written on disks
larger than 2 TB. When format is invoked with the -e option, on
writing the label, the label type can be chosen. Booting is not
currently supported on a disk with an EFI label.

NOTES

format provides a help facility you can use whenever format is
expecting input. You can request help about what information is
expected by simply entering a question mark (?) and format prints a
brief description of what type of input is needed. If you enter a ?
at the menu prompt, a list of available commands is displayed.


For SCSI disks, formatting is done with both Primary and Grown
defects list by default. However, if only Primary list is extracted
in defect menu before formatting, formatting will be done with
Primary list only.


Changing the state of the caches is only supported on SCSI devices,
and not all SCSI devices support changing or saving the state of the
caches.


The NCSC-TG-025 algorithm for overwriting meets the DoD 5200.28-M
(ADP Security Manual) Eraser Procedures specification. The NIST
Guidelines for Media Sanitization (NIST SP 800-88) also reference
this algorithm.

August 29, 2021 FORMAT(8)