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.
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
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.
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 the table below.
Table 32-6 format.dat Keyword Descriptions
Keyword |
Use |
---|---|
search_path |
This keyword is no longer used in the format.dat file. Starting with the Solaris 2.0 release, the format utility searchs the logical device hierarchy (/dev) so there is no need to set this keyword to find a system's disks. |
disk_type |
Defines the controller and disk model. Each disk_type definition contains information concerning 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. |
partition |
Defines a slice table for a specific disk type. The slice table contains the slice information, plus a name that lets you refer to it in format. The default data file contains default slice definitions for several kinds of disk drives. Add a slice definition if you recreated slices on any of the disks on your system. Add as many slice definitions to the data file as you need. |
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. The table below describes the identifiers that must also be assigned values in all disk_type definitions.
Table 32-7 Required disk_type Identifiers
Identifier |
Description |
---|---|
ctlr |
Valid controller type for the disk type. Currently, the supported values for this assignment are SCSI and ISP-80 (IPI controller). |
ncyl |
The number of data cylinders in the disk type. This determines how many logical cylinders of the disk the system will be allowed to access. |
acyl |
The number of alternate cylinders in the disk type. These cylinders are used by format to store information such as the defect list for the drive. You should always leave at least two cylinders for alternates. |
pcyl |
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 |
The number of heads in the disk type. This number is used to calculate the boundaries of the disk media. |
nsect |
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 is only the data sectors, any spares are not reflected in the assignment. |
rpm |
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 assignments might be necessary depending on the controller. The table below describes the assignments required for SCSI controllers.
Table 32-8 disk_type Identifiers for SCSI Controllers
Identifier |
Description |
---|---|
fmt_time |
A number indicating how long it takes to format a given drive. See the controller manual for more information. |
cache |
A number that controls the operation of the onboard cache while format is operating. See the controller manual for more information. |
trks_zone |
A number that specified how many tracks you have per defect zone, to be used in alternate sector mapping. See the controller manual for more information. |
asect |
The number assigned to this parameter specifies how many sectors are available for alternate mapping within a given defect zone. See the controller manual for more information. |
Below are some 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 |
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. The table below describes the identifiers that must be assigned values in all slice tables.
Table 32-9 Required Identifiers for Slice Tables
Identifier |
Description |
---|---|
disk |
The name of the disk_type that this slice table is defined for. This name must appear exactly as it does in the disk_type definition. |
ctlr |
The disk controller type this slice table can be attached to. Currently, the supported values for this assignment are ISP-80 for IPI controllers and SCSI for SCSI controllers. The controller type specified here must also be defined for the disk_type chosen above. |
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 = "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 |
The format utility learns of the location of your data file by the following methods.
If a filename is given with the -x command line option, that file is always used as the data file.
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.
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.