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 15–6 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 15–7 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 15–8 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 15–1 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
|
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