Files Used by format--format.dat

The format data file, /etc/format.dat, contains:

• Disk types

• Default slice tables

The format.dat file shipped with the Solaris operating environment supports many standard disks. If your disk drive is not listed in the format.dat file, you can choose to add an entry for it or allow format to prompt you for the information it needs while it is performing operations.

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 you added to the format.dat file.

You should modify the data file for your system if you have one of the following:

• A disk that is not supported by the Solaris operating environment

• A disk with a slice table that is different from the Solaris operating environment default configuration

Do not alter default entries. If you want to alter the default entries, copy the entry, give it a different name, and make the modification to avoid confusion.

Structure

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

• Search paths

• Disk types

• Slice tables

Syntax

The following syntax rules apply to the data file:

• The pound sign (#) is the comment character. Any text on a line after a pound sign is not interpreted by format.

• Each definition in the format.dat file appears on a single logical line. If the definition is more than one line long, all 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 format. If you want an assigned value to contain white space, enclose the entire value in double quotes ("). This will cause the white space within the quotes to be preserved as part of the assignment value.

• Some assignments can have multiple values on the right hand side. Separate values by a comma.

Keywords

The data file contains disk definitions that are read in by format when it is started. Each definition starts with one of the following keywords: search_path, disk_type, and partition, which are described in Table 25-6.

Disk Type

disk_type defines the controller and disk model. Each disk_type definition contains the physical geometry of the disk. The default data file contains definitions for the controllers and disks that the Solaris operating environment 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 format is run. Enclose the name in double quotes to preserve any white space in the name. Table 25-7 describes the identifiers that must also be assigned values in all disk_type definitions.

Other assignments may be necessary depending on the controller. Table 25-8 describes the assignments required for SCSI controllers.

Below are some examples of disk_type definitions:

disk_type = "SUN0535" \
	: ctlr = SCSI : fmt_time = 4 \
	: ncyl = 1866 : acyl = 2 : pcyl = 2500 : nhead = 7 : nsect = 80 \
	: rpm = 5400
disk_type = "SUN0669" \
	: ctlr = SCSI : fmt_time = 4 \
	: trks_zone = 15 : asect = 5 : atrks = 30 \
	: ncyl =  1614 : acyl = 2 : pcyl = 1632 : nhead = 15 : nsect = 54 \
	: rpm = 3600 : bpt = 31410
disk_type = "SUN1.0G" \
	: ctlr = SCSI : fmt_time = 4 \
	: trks_zone = 15 : asect = 5 : atrks = 30 \
	: ncyl =  1703 : acyl = 2 : pcyl = 1931 : nhead = 15 : nsect = 80 \
	: rpm = 3597 : bpt = 41301

Slice Tables

A partition definition keyword is assigned the name of the slice table. Enclose the name in double quotes to preserve any white space in the name. Table 25-9 describes the identifiers that must be assigned values in all slice tables.

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

partition = "SUN0535" \
	: disk = "SUN0535" : ctlr = SCSI \
	: 0 = 0, 64400 : 1 = 115, 103600 : 2 = 0, 1044960 : 6 = 300, 876960
partition = "SUN0669" \
	: disk = "SUN0669" : ctlr = SCSI \
	: 0 = 0, 32400 : 1 = 40, 64800 : 2 = 0, 1307340 : 6 = 120, 1210140
partition = "SUN1.0G" \
	: disk = "SUN1.0G" : ctlr = SCSI \
	: 0 = 0, 32400 : 1 = 27, 64800 : 2 = 0, 2043600 : 6 = 81, 1946400

Location

The format utility learns of the location of your data file by the following methods.

1. If a filename is given with the -x command line option, that file is always used as the data file.

2. If the -x option is not specified, then format looks in the current directory for a file named format.dat. If the file exists, it is used as the data file.

3. If neither of these methods yields a data file, format uses /etc/format.dat as the data file. This file is shipped with the Solaris operating environment and should always be present.