test

System Administration Guide, Volume 1

Keywords in the format.dat File

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 (format.dat)

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