DISK(8)DISK(8)NAMEdisk - 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 ALSOdisktab(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.
NeXT Computer, Inc. March 3, 1990 DISK(8)
