System Administration Guide: Devices and File Systems

Chapter 16 The `format` Utility (Reference)

This chapter describes the format utility's menus and commands.

This is a list of the reference information in this chapter.

For a overview of when to use the format utility, see format Utility.

Recommendations and Requirements for Using the `format` Utility

You must be superuser or have assumed an equivalent role to use the format utility. Otherwise, the following error message is displayed when you try to use the format utility:

$ format
Searching for disks...done
No permission (or no disks found)!

Keep the following guidelines in mind when you use the format utility and want to preserve the existing data:

Back up all files on the disk drive.
Save all your defect lists in files by using the format utility's dump command. The file name should include the drive type, model number, and serial number.
Save the paper copies of the manufacturer's defect list that was shipped with your drive.

`format` Menu and Command Descriptions

The format main menu appears similar to the following:

FORMAT MENU:
        disk       - select a disk
        type       - select (define) a disk type
        partition  - select (define) a partition table
        current    - describe the current disk
        format     - format and analyze the disk
        fdisk      - run the fdisk program (x86 only)
        repair     - repair a defective sector
        label      - write label to the disk
        analyze    - surface analysis
        defect     - defect list management
        backup     - search for backup labels
        verify     - read and display labels
        save       - save new disk/partition definitions
        inquiry    - show vendor, product and revision
        volname    - set 8-character volume name
        !<cmd>     - execute <cmd>, then return
        quit
format>

The following table describes the main menu items for the format utility.

Table 16–1 The Main Menu Item Descriptions for the format Utility


Menu Item	Command or Menu?	Description
`disk`	Command	Lists all of the system's drives. Also lets you choose the disk you want to use in subsequent operations. This disk is referred to as the current disk.
`type`	Command	Identifies the manufacturer and model of the current disk. Also displays a list of known drive types. Choose the `Auto configure` option for all SCSI-2 disk drives.
`partition`	Menu	Creates and modifies slices. For more information, see `partition` Menu.
`current`	Command	Displays the following information about the current disk: Device name and device type Number of cylinders, alternate cylinders, heads and sectors Physical device name
`format`	Command	Formats the current disk by using one of these sources of information in this order: Information that is found in the `format.dat` file Information from the automatic configuration process Information that you type at the prompt if no `format.dat` entry exists This command does not apply to IDE disks. IDE disks are preformatted by the manufacturer.
`fdisk`	Menu	x86 platform only: Runs the `fdisk` program to create a Solaris `fdisk` partition. The `fdisk` command cannot be used on disks with an EFI label that are greater than 1 terabyte in size.
`repair`	Command	Repairs a specific block on the current disk.
`label`	Command	Writes a new label to the current disk.
`analyze`	Menu	Runs read, write, and compare tests. For more information, see `analyze` Menu.
`defect`	Menu	Retrieves and displays defect lists. For more information, see `defect` Menu. This feature does not apply to IDE disks. IDE disks manage defects automatically.
`backup`	Command	VTOC – Searches for backup labels. EFI – Not supported.
`verify`	Command	Displays the following information about the current disk: Device name and device type Number of cylinders, alternate cylinders, heads and sectors Partition table
`save`	Command	VTOC – Saves new disk and partition information. EFI – Not applicable.
`inquiry`	Command	SCSI disks only – Displays the vendor, product name, and revision level of the current drive.
`volname`	Command	Labels the disk with a new eight-character volume name that you specify.
`quit`	Command	Exits the `format` menu.

`partition` Menu

The partition menu appears similar to the following:

format> partition
PARTITION MENU:
        0      - change `0' partition
        1      - change `1' partition
        2      - change `2' partition
        3      - change `3' partition
        4      - change `4' partition
        5      - change `5' partition
        6      - change `6' partition
        7      - change `7' partition
        select - select a predefined table
        modify - modify a predefined partition table
        name   - name the current table
        print  - display the current table
        label  - write partition map and label to the disk
        quit
partition>

The following table describes the partition menu items.

Table 16–2 Descriptions for partition Menu Items


Subcommand	Description
change ``n' partition`	Enables you to specify the following information for the new partition: Identification tag Permission flags Starting cylinder Size
`select`	Enables you to choose a predefined partition table.
`modify`	Enables you to change all the slices in the partition table. This command is preferred over the individual `change` ``x`' `partition` commands.
`name`	Enables you to specify a name for the current partition table.
`print`	Displays the current partition table.
`label`	Writes the partition map and the label to the current disk.
`quit`	Exits the `partition` menu.

x86: `fdisk` Menu

The fdisk menu appears on x86 based systems only and appears similar to the following.

format> fdisk
             Total disk size is 14169 cylinders
             Cylinder size is 2510 (512 byte) blocks

                                               Cylinders
      Partition   Status    Type          Start   End   Length    %
      =========   ======    ============  =====   ===   ======   ===
          1       Active    x86 Boot          1     9       9      0
          2                 Solaris2         10  14168    14159    100

SELECT ONE OF THE FOLLOWING:

  1. Create a partition
  2. Specify the active partition
  3. Delete a partition
  4. Change between Solaris and Solaris2 Partition IDs
  5. Exit (update disk configuration and exit)
  6. Cancel (exit without updating disk configuration)
  Enter Selection:

The following table describes the fdisk menu items.

Table 16–3 x86: Descriptions for fdisk Menu Items


Menu Item	Description
`Create a partition`	Creates an `fdisk` partition. You must create a separate partition for each OS such as Solaris or DOS. There is a maximum of four partitions per disk. You are prompted for the size of the `fdisk` partition as a percentage of the disk.
`Specify the active partition`	Enables you to specify the partition to be used for booting. This menu item identifies where the first stage boot program looks for the second stage boot program.
`Delete a partition`	Deletes a previously created partition. This command destroys all the data in the partition.
`Change between Solaris and Solaris2 Partition IDs`	Changes partition IDs from 130 (`0x82`) to 191 (`0xbf`) and back again.
`Exit (update disk configuration and exit)`	Writes a new version of the partition table and exits the `fdisk` menu.
`Cancel (exit without updating disk configuration)`	Exits the `fdisk` menu without modifying the partition table.

`analyze` Menu

The analyze menu appears similar to the following.

format> analyze
 
ANALYZE MENU:
    read     - read only test   (doesn't harm SunOS)
    refresh  - read then write  (doesn't harm data)
    test     - pattern testing  (doesn't harm data)
    write    - write then read      (corrupts data)
    compare  - write, read, compare (corrupts data)
    purge    - write, read, write   (corrupts data)
    verify   - write entire disk, then verify (corrupts data)
    print    - display data buffer
    setup    - set analysis parameters
    config   - show analysis parameters
    quit
analyze>

The following table describes the analyze menu items.

Table 16–4 Descriptions for analyze Menu Items


Subcommand	Description
`read`	Reads each sector on the current disk. Repairs defective blocks as a default.
`refresh`	Reads then writes data on the current disk without harming the data. Repairs defective blocks as a default.
`test`	Writes a set of patterns to the disk without harming the data. Repairs defective blocks as a default.
`write`	Writes a set of patterns to the disk then reads back the data on the disk. Destroys existing data on the disk. Repairs defective blocks as a default.
`compare`	Writes a set of patterns to the disk, reads back the data, and then compares it to the data in the write buffer. Destroys existing data on the disk. Repairs defective blocks as a default.
`purge`	Removes all data from the disk so that the data cannot be retrieved by any means. Data is removed by writing three distinct patterns over the entire disk (or a section of the disk). If the verification passes, a hex-bit pattern is written over the entire disk (or a section of the disk). Repairs defective blocks as a default.
`verify`	In the first pass, writes unique data to each block on the entire disk. In the next pass, reads and verifies the data. Destroys existing data on the disk. Repairs defective blocks as a default.
`print`	Displays the data in the read/write buffer.
`setup`	Enables you to specify the following analysis parameters: Analyze entire disk? yes Starting block number: `depends on drive` Ending block number: `depends on drive` Loop continuously? no Number of passes: 2 Repair defective blocks? yes Stop after first error? no Use random bit patterns? no Number of blocks per transfer: 126 (0/`n`/`nn`) Verify media after formatting? yes Enable extended messages? no Restore defect list? yes Restore disk label? yes
`config`	Displays the current analysis parameters.
`quit`	Exits the `analyze` menu.

`defect` Menu

The defect menu appears similar to the following:

format> defect
 
DEFECT MENU:
        primary  - extract manufacturer's defect list
        grown    - extract manufacturer's and repaired defects lists
        both     - extract both primary and grown defects lists
        print    - display working list
        dump     - dump working list to file
        quit
defect>

The following table describes the defect menu items.

Table 16–5 The defect Menu Item Descriptions


Subcommand	Description
`primary`	Reads the manufacturer's defect list from the disk drive and updates the in-memory defect list.
`grown`	Reads the grown defect list and then updates the in-memory defect list. Grown defects are defects that have been detected during analysis.
`both`	Reads both the manufacturer's defect list and the grown defect list. Then, updates the in-memory defect list.
`print`	Displays the in-memory defect list.
`dump`	Saves the in-memory defect list to a file.
`quit`	Exits the `defect` menu.

`format.dat` File

The format.dat file that is shipped with the Solaris OS supports many standard disks. If your disk drive is not listed in the format.dat file, you can do the following:

Add an entry to the format.dat file for the disk.
Add entries with the format utility by selecting the type command and choosing the other option.

Adding an entry to the format.dat file can save time if the disk drive will be used throughout your site. To use the format.dat file on other systems, copy the file to each system that will use the specific disk drive that you added to the format.dat file.

You might need to modify the /etc/format.dat file for your system if you have one of the following:

A disk that is not supported by the Solaris OS
A disk with a partition table that is different from the Solaris OS's default configuration

Note –

Do not alter default entries in the /etc/format.dat file. If you want to alter the default entries, copy the entry, give the entry a different name, and make the appropriate changes to avoid confusion.

The /etc/format.dat is not applicable for disks with EFI labels.

Contents of the `format.dat` File

The format.dat contains disk drive information that is used by the format utility. Three items are defined in the format.dat file:

Search paths
Disk types
Slice tables

Syntax of the `format.dat` File

The following syntax rules apply to the /etc/format.dat file:

The pound sign (#) is the comment character. Any text on a line after a pound sign is not interpreted by the format utility.
Each definition in the format.dat file appears on a single logical line. If the definition is longer than one line long, all lines but the last line of the definition must end with a backslash (\).
A definition consists of a series of assignments that have an identifier on the left side and one or more values on the right side. The assignment operator is the equal sign (=). The assignments within a definition must be separated by a colon (:).
White space is ignored by the format utility. If you want an assigned value to contain white space, enclose the entire value in double quotation marks ("). This syntax causes the white space within the quotes to be preserved as part of the assignment value.
Some assignments can have multiple values on the right side. Separate values by a comma.

Keywords in the `format.dat` File

The format.dat file contains disk definitions that are read by the format utility when it is started. Each definition starts with one of the following keywords: disk_type or partition. These keywords are described in the following table.

Table 16–6 Keyword Descriptions for the format.dat File


Keyword	Description
`disk_type`	Defines the controller and disk model. Each `disk_type` definition contains information that concerns the physical geometry of the disk. The default data file contains definitions for the controllers and disks that the Solaris OS supports. You need to add a new `disk_type` definition only if you have an unsupported disk. You can add as many `disk_type` definitions to the data file as you want.
`partition`	Defines a partition table for a specific disk type. The partition table contains the partition information, plus a name that lets you refer to it in the `format` utility. The default `format.dat` file contains default partition definitions for several kinds of disk drives. Add a partition definition if you recreated partitions on any of the disks on your system. Add as many partition definitions to the data file as you need.

Disk Type (`format.dat`)

The disk_type keyword in the format.dat file defines the controller and disk model. Each disk_type definition contains information about the physical geometry of the disk. The default format.dat file contains definitions for the controllers and disks that the Solaris OS supports. You need to add a new disk_type only if you have an unsupported disk. You can add as many disk_type definitions to the data file as you want.

The keyword itself is assigned the name of the disk type. This name appears in the disk's label, and is used to identify the disk type whenever the format utility is run. Enclose the name in double quotation marks to preserve any white space in the name. The following table describes the identifiers that must also be assigned values in all disk_type definitions.

Table 16–7 Required disk_type Identifiers (format.dat)


Identifier	Description
`ctlr`	Identifies the controller type for the disk type. Currently, the supported values are SCSI and ATA.
`ncyl`	Specifies the number of data cylinders in the disk type. This determines how many logical disk cylinders the system will be allowed to access.
`acyl`	Specifies the number of alternate cylinders in the disk type. These cylinders are used by the `format` utility to store information such as the defect list for the drive. You should always reserve at least two cylinders for alternates.
`pcyl`	Specifies the number of physical cylinders in the disk type. This number is used to calculate the boundaries of the disk media. This number is usually equal to `ncyl` plus `acyl`.
`nhead`	Specifies the number of heads in the disk type. This number is used to calculate the boundaries of the disk media.
`nsect`	Specifies the number of data sectors per track in the disk type. This number is used to calculate the boundaries of the disk media. Note that this number includes only the data sectors. Any spares are not reflected in the number of data sections per track.
`rpm`	Specifies the rotations per minute of the disk type. This information is put in the label and later used by the file system to calculate the optimal placement of file data.

Other identifiers might be necessary, depending on the controller. The following table describes the identifiers that are required for SCSI controllers.

Table 16–8 Required disk_type Identifiers for SCSI Controllers format.dat


Identifier	Description
`fmt_time`	Specifies a number that indicates how long it takes to format a given drive. See the controller manual for more information.
`cache`	Specifies a number that controls the operation of the on-board cache while the `format` utility is operating. See the controller manual for more information.
`trks_zone`	Specifies a number that identifies how many tracks that exist per defect zone, to be used in alternate sector mapping. See the controller manual for more information.
`asect`	Specifies a number that identifies how many sectors are available for alternate mapping within a given defect zone. See the controller manual for more information.

Example 16–1 Required `disk_type` Identifiers for SCSI Controllers (`format.dat`)

The following are examples of disk_type definitions:

disk_type = "SUN1.3G" \
        : ctlr = SCSI : fmt_time = 4 \
        : trks_zone = 17 : asect = 6 : atrks = 17 \
        : ncyl = 1965 : acyl = 2 : pcyl = 3500 : nhead = 17 : nsect = 80 \
        : rpm = 5400 : bpt = 44823

disk_type = "SUN2.1G" \
        : ctlr = SCSI : fmt_time = 4 \
        : ncyl = 2733 : acyl = 2 : pcyl = 3500 : nhead = 19 : nsect = 80 \
        : rpm = 5400 : bpt = 44823

disk_type = "SUN2.9G" \
        : ctlr = SCSI : fmt_time = 4 \
        : ncyl = 2734 : acyl = 2 : pcyl = 3500 : nhead = 21 : nsect = 99 \
        : rpm = 5400

Partition Tables (`format.dat`)

A partition table in the format.dat file defines a slice table for a specific disk type.

The partition keyword in the format.dat file is assigned the name of the partition table. Enclose the name in double quotation marks to preserve any white space in the name. The following table describes the identifiers that must be assigned values in all partition tables.

Table 16–9 Required Identifiers for Partition Tables (format.dat)


Identifier	Description
`disk`	The name of the `disk_type` that this partition table is defined for. This name must appear exactly as it does in the `disk_type` definition.
`ctlr`	The disk controller type that this partition table can be attached to. Currently, the supported values are ATA for ATA controllers and SCSI for SCSI controllers. The controller type that is specified here must also be defined for the `disk_type` that you specified in the `disk_type` definition.

The other identifiers in a slice definition describe the actual partition information. The identifiers are the numbers 0 through 7. These identifiers are optional. Any partition that is not explicitly assigned is set to 0 length. The value of each of these identifiers is a pair of numbers separated by a comma. The first number is the starting cylinder for the partition. The second is the number of sectors in the slice.

Example 16–2 Required Identifiers for Partition Tables (`format.dat`)

The following are some examples of slice definitions:

partition = "SUN1.3G" \
        : disk = "SUN1.3G" : ctlr = SCSI \
        : 0 = 0, 34000 : 1 = 25, 133280 : 2 = 0, 2672400 : 6 = 123, 2505120

partition = "SUN2.1G" \
        : disk = "SUN2.1G" : ctlr = SCSI \
        : 0 = 0, 62320 : 1 = 41, 197600 : 2 = 0, 4154160 : 6 = 171, 3894240

partition = "SUN2.9G" \
        : disk = "SUN2.9G" : ctlr = SCSI \
        : 0 = 0, 195426 : 1 = 94, 390852 : 2 = 0, 5683986 : 6 = 282, 5097708

Specifying an Alternate Data File for the `format` Utility

The format utility determines the location of an alternate file by the following methods in this order:

If a file name is given with the format -x option, that file is always used as the data file.
If the -x option is not specified, then the format utility searches the current directory for a file named format.dat. If the file exists, it is used as the data file.
If neither of these methods yields a data file, the format utility uses the /etc/format.dat file as the data file. This file is shipped with the Solaris OS and should always be present.

Rules for Input to `format` Commands

When you use the format utility, you need to provide various kinds of information. This section describes the rules for this information. For information on using format's help facility when you specify data, see Getting Help on the format Utility.

Specifying Numbers to `format` Commands

Several places in the format utility require number as input. You must either specify the appropriate data or select a number from a list of choices. In either case, the help facility causes format to display the upper and lower limits of the number expected. Simply enter the appropriate number. The number is assumed to be in decimal format unless a base is explicitly specified as part of the number (for example, 0x for hexadecimal).

The following are examples of integer input:

Enter number of passes [2]: 34 
Enter number of passes [34] Oxf

Specifying Block Numbers to `format` Commands

Whenever you are required to specify a disk block number, there are two ways to do so:

Specify the block number as an integer
Specify the block number in the cylinder/head/sector format

You can specify the information as an integer that represents the logical block number. You can specify the number in any base, but the default is decimal. The maximum operator (a dollar sign, $) can also be used here so that format utility can select the appropriate value. Logical block format is used by the SunOS disk drivers in error messages.

The other way to specify a block number is by using cylinder/head/sector format. In this method, you must specify explicitly the three logical components of the block number: the cylinder, head, and sector values. These values are still logical. However, they allow you to define regions of the disk that are related to the layout of the media.

If any of the cylinder/head/sector numbers are not specified, the value is assumed to be zero. You can also use the maximum operator in place of any of the numbers. Then, the format utility will select the appropriate value. The following are some examples of cylinder, head, and sector values:

Enter defective block number: 34/2/3
Enter defective block number: 23/1/
Enter defective block number: 457//
Enter defective block number: 12345
Enter defective block number: Oxabcd
Enter defective block number: 334/$/2
Enter defective block number: 892//$

The format utility always displays block numbers in both formats. Also, the help facility shows you the upper and lower limits of the block number expected, in both formats.

Specifying `format` Command Names

Command names are needed as input whenever the format utility displays a menu prompt. You can abbreviate the command names, as long as what you type is sufficient to uniquely identify the command desired.

For example, use p to access the partition menu from the format menu. Then, type p to display the current slice table.

format> p
PARTITION MENU:
        0      - change `0' partition
        1      - change `1' partition
        2      - change `2' partition
        3      - change `3' partition
        4      - change `4' partition
        5      - change `5' partition
        6      - change `6' partition
        7      - change `7' partition
        select - select a predefined table
        modify - modify a predefined partition table
        name   - name the current table
        print  - display the current table
        label  - write partition map and label to the disk
        quit
partition> p

Specifying Disk Names to `format` Commands

At certain points in the format utility, you must name something. In these cases, you are free to specify any string you want for the name. If the name has white space in it, the entire name must be enclosed in double quotation marks ("). Otherwise, only the first word of the name is used.

For example, if you want to identify a specific partition table for a disk, you can use the name subcommand that is available from the partition menu:

partition> name
Enter table name (remember quotes): "new disk3"

Getting Help on the `format` Utility

The format utility provides a help facility that you can use whenever the format utility is expecting input. You can request help about what input is expected by typing a question mark (?). The format utility displays a brief description of what type of input is needed.

If you type a ? at a menu prompt, a list of available commands is displayed.

The man pages associated with the format utility include the following:

format(1M) – Describes the basic format utility capabilities and provides descriptions of all command-line variables.
format.dat(4) – Describes disk drive configuration information for the format utility.

Chapter 16 The format Utility (Reference)

Recommendations and Requirements for Using the format Utility

format Menu and Command Descriptions

partition Menu

x86: fdisk Menu

analyze Menu

defect Menu

format.dat File

Contents of the format.dat File

Syntax of the format.dat File

Keywords in the format.dat File

Disk Type (format.dat)

Example 16–1 Required disk_type Identifiers for SCSI Controllers (format.dat)

Partition Tables (format.dat)

Example 16–2 Required Identifiers for Partition Tables (format.dat)

Specifying an Alternate Data File for the format Utility

Rules for Input to format Commands

Specifying Numbers to format Commands

Specifying Block Numbers to format Commands

Specifying format Command Names

Specifying Disk Names to format Commands

Getting Help on the format Utility