Format utility: to discover the types of disks that are connected to a system. You can also use the
format utility to verify that a disk is known to the system.
Identifying the Disks on a System
#format
display the disks connected to a second controller
# format /dev/rdsk/c2*
Formatting a Disk:
A disk must be formatted before:
- You can write data to it. However, most disks are already formatted.
- You can use the Solaris installation program to install the system.
Displaying Disk Slices
You can use the format utility to check whether or not a disk has the appropriate disk slices. If you determine that a
disk does not contain the slices you want to use, use the format utility to re-create them and label the disk.
Creating and Examining a Disk Label
Labeling a disk is usually done during system installation or when you are creating new disk slices. You may need to
relabel a disk if the disk label is corrupted (for example, from a power failure).
The format utility will attempt to automatically configure any unlabeled SCSI disk. If format is able to automatically
configure an unlabeled disk, it will display a message like the following:
c1t0d0: configured with capacity of 404.65MB
format.dat - disk drive configuration for the format command.
Key Words
search_path:
4.x: tells format which disks it should search for when it starts up. The lists in the default data file contains
all the disks in the GENERIC configuration file. If your system has disks that are not in the GENERIC configuration
file, add them to the search_path definition in your data file. The data file can contain only one search_path
definition lets you specify all the disks you have in your system.
5.x: by default, format understands all the logical devices that are of the form: /dev/rdsk/cntndnsn;
hence search_path is not normally defined on a 5.x system.
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 system 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 as you want
The following controller types are supported by format:
XY450: Xylogics 450 controller (SMD)
MD7053: Xylogics 7053 controller (SMD)
MID21: SCSI, but using ESDI devices (aka shoebox)
SCSI: true SCSI (CCS or SCSI-2)
ISP-80: IPI panther controller
Note: the disk_type and partition definition entries must have "ctlr=MD21" for scsi disk device
for 4.1.1 release. But for 4.1.2, 4.1.3, and 5.x release, the entries should say "stlr=SCSI".
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.
Below are the list of identifiers for supported controllers.
Note: that an asterisk(*) indicates the identifier is mandatory for that controller
-- it is not part of the keyword name.
acyl* -alternate cylinders
asect -alternate sectors per track
atrks -alternate tracks
fmt_time -formatting time per cylinder
ncyl* -number of logical cylinders
nhead* -number of logical head
nsect* -number of logical sectors per track
pcyl* -number of phycical cylinders
phead -number of physical heads
psect -number of physical sectors per track
rpm* -drive RPM
These identifiers are for SCSI and MD-21 controllers:
read_retries --> page 1 byte 3 (read retries)
write_retries --> page 1 byte 8 (write retries)
cyl_skew --> page 3 bytes 18-19 (cylinder skew)
trk_skew --> page 3 bytes 18-19 (track skew)
trks_zone --> page 3 bytes 2-3 (tracks per zone)
cache --> page 38 bytes 2 (cache parameter)
prefetch --> page 38 byte 3 (prefetch parameter)
max_prefetch --> page 38 byte 4 (minimum prefetch)
min_prefetch --> page 38 byte 6 (maximum prefetch)
Note: The page 38 values are device-specific. Refer the user to the particular disk's manual for this
values.
For SCSI disks, the following geometric specifier may cause a mode on the byte indicate.
asect --> page 3 byte 4-5 (alternate sectors per zone)
atrks --> page 3 byte 8-9 (alt. tracks per logical unit)
phead --> page 4 byte 5 (number of heads)
psect --> page 3 byte 10-11 (sectors per track)
These identifiers are for SMD controllers only
bps* --> bytes per sector (SMD)
bpt* --> bytes per track (SMD)
Note: under SunOS 5.x, bpt is only required for SMD disk Under SunOS 4.x, bpt was required for all disk
types, even though it was only used for SMD disks.
And this identifier is for XY450 SMD Controllers Only
drive_type* --> drive type (SMD) (just call this "xy450 drive type")
partition --> Defines a partition table for a specific disk type. The partition table contains the
partitioning information, plus a name that lets you refer to it in format(1M). The
default data file contains default parition definitions for several kinds of disk drives.
Add a partition definition if you repartitioned any of the disks on your system. Add as
many partition definitions to the data file as you need.
Partition naming conventions differ in SunOS 4.x and in SunOS 5.x.
4.x: the partitions are named as a ,b, c, d, e ,f, g, h.
5.x: the partitions are referred to by numbers 0 ,1 ,2 ,3 ,4 ,5 ,6 ,7 .
EXAMPLES
Following is a sample disk_type and partition definition in format.dat file for SUN0535 disk device.
disk_type = "SUN0535" \
: ctlr = SCSI : fmt_time = 4 \
: ncyl = 1866 : acyl = 2 : pcyl = 2500 : nhead = 7 : nsect = 80 \
: rpm = 5400
partition = "SUN0535" \
: disk = "SUN0535" : ctlr = SCSI \
: 0 = 0, 64400 : 1 = 115, 103600 : 2 = 0, 1044960 : 6 = 300, 876960
FILES
/etc/format.dat
default data file if format -x is not specified, nor is there a format.dat file in the current directory.
Consider two SCSI disks you found in class. You need to partition 100 similar new disks into three equal slices: Slice 0, Slice 1, and Slice4. Doing it manually would be insane! Prepare two possible entries in the /etc/format.dat based on the information you have or can get from the manufacturer's web page.
# #Following is a list of SCSI disk configuration # disk_type = "DORS"\ : ctlr = SCSI : fmt_time = 4 \ : ncyl = 8186 : acyl = 2 :pcyl = 8188 : nhead = 3 : nsect = 171 \ : rpm = 5400
# # This is the list of partition tables for embedded SCSI controllers. # partition = "DORS" \ : disk = "DORS" : ctlr = SCSI \ : 0 = 0, 1408908 : 1 = 77, 1408908 : 2 = 0, 4226725 : 6 = 211, 1408908