DISK
Section: Maintenance Commands (8)
Updated: March 3, 1990
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NAME
disk - disk initialization and diagnosis
SYNOPSIS
/usr/etc/disk
[
option flags
]
[
action flags
]
raw-device
DESCRIPTION
The
disk
utility program can be used to initialize,
inspect, repair, and configure optical, floppy and SCSI disks.
The
option flags
are used with the
-i
action flag to specify certain parameters when initializing a disk:
- -h hostname
-
Specifies a
hostname
to be stored in the disk label.
The actual hostname of a machine
is not determined by the disk label,
but in the case of removable optical media
this field may be set for informational purposes
to indicate which machine the disk belongs to.
- -l labelname
-
The
labelname
of a disk is printed in the message log when the system boots.
For optical media this is also the name used as the mount point
in the / directory when the disk is automounted.
- -t disk_type
-
The disk configuration information in
/etc/disktab
is named by an identifier called the
disk type.
By default, when the
disk
program is run it will attempt to determine the proper
disk type
to use.
Use this flag to override the default.
This is used to reinitialize a disk using a different
set of configuration parameters from
/etc/disktab
(e.g. a different number and/or size of filesystem partition(s)).
The
action flags
are used to perform a specific command in the disk program
(only one may be specified):
- -i
-
This flag will initialize a disk including writing out a new disk label
containing information about the host name, label name and information
found in
/etc/disktab.
A boot program will be installed onto the boot block area of the
disk from the file
/usr/standalone/boot.
If specified in the configuration information in
/etc/disktab,
the initialize flag will also build empty UNIX filesystems on the disk.
The initialize flag will destroy all data on the disk.
WARNING:
Don't initialize a mounted device.
Example: "/etc/disk -h myhost -l mydisk -i /dev/rod0a"
- -e
-
This flag will eject ejectable media.
No attempt is made
to unmount the filesystems on this disk before ejecting.
- -b
-
The boot program in
/usr/standalone/boot
will be written onto the boot block area of the disk.
- -B
-
Same as
-b,
except that it takes
as an argument
the pathname of the file
containing data to be written
onto the boot block area of the disk.
- -p partitionsize
-
The first partition of a two-partition disk will be
partitionsize,
and the second partition uses the remainder of the disk.
The
partitionsize
is in units
of the native blocksize
of the device
(minimum 1K).
The
-p
option only has meaning
when used with
-i.
- -q
-
The default
disk type
information returned by the device driver for this disk
will be printed.
This flag is used by the
Builddisk
application to determine what kind of disk is present.
- -s
-
If the device driver keeps any special statistics for the disk
they will be printed with this flag.
- -F
-
This flag formats the disk.
- -H hostname
-
This flag can be used to change the
hostname
field of the disk label without disturbing other fields in the label.
- -L labelname
-
This flag can be used to change the
labelname
field of the disk label without disturbing other fields in the label.
If no
action flags
are specified the program operates in an interactive mode.
In interactive mode type the interrupt character at any time
to abort the current command.
Typing '?' will list the available commands.
Many of the commands will prompt for additional arguments or sub-commands.
There are many interactive commands in addition to the ones described
by the
option flags
above:
- read, write, verify, rw, rwr
-
These commands will read, write and verify data on the disk.
All block numbers used in these commands are absolute disk block numbers
and do not correspond to block numbers reported from the filesystem.
No bad sector forwarding or additions are performed with these commands.
On an optical disk, these commands can be used to write a sector
that has become unreadable due to an uncorrectable ECC errors.
WARNING:
These commands may destroy disk data.
- look, set
-
These commands may be used to inspect and modify the data buffers used
in the read and write commands described above.
- abort
-
This command toggles whether an error will stop the read and write
commands described above.
- label
-
This command is used to print and change information in the disk label.
To change only the hostname or labelname fields use the
-H hostname
or
-L labelname
action flags described earlier.
- bad
-
Use this command to display and edit the bad block table maintained
on optical disks.
- bitmap
-
Use this command to display and edit
the sector status bitmap maintained on optical disks.
- scan
-
The scan command sequentially searches the disk for file system super blocks
and prints the file system block number where they are found.
This information is essential
if the primary super block of a file system is damaged
and one needs to specify an alternate super block location
to the file system check program
fsck
but one does not know which block number to specify.
(e.g. "fsck -bnnn /dev/rod0a" where "nnn" is the block number of the alternate
super block).
A list of these block numbers is produced
when a file system is initialized with the
newfs
command,
but this list usually isn't around when needed.
FILES
- /etc/disktab
-
for disk geometry and partition layout information
- /usr/standalone/boot
-
the default program written onto the boot block area
SEE ALSO
disktab(5)
BUGS
Like all low-level diagnostics written early in the life of a new computer,
this program exhibits evolutionary development.
Some features may be difficult to understand
or not work exactly as advertised.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- FILES
-
- SEE ALSO
-
- BUGS
-
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