mediainit(1)mediainit(1)NAMEmediainit - initialize disk or partition DDS tape
SYNOPSIS
fmt_optn] interleave] size] pathname
scrub_character] scrub_count] special_file
DESCRIPTION
initializes mass storage media by formatting the media, writing and
reading test patterns to verify media integrity, then sparing any
defective blocks found. This process prepares the disk or tape for
error-free operation. Initialization destroys all existing user data
in the area being initialized.
can also be used for partitioning DDS tape media. See the option below
for further details.
can also be used for disk scrubbing. Disk scrubbing is the process of
overwriting the entire disk with a single character. See the option
below for further details.
Options
The following command options are recognized. They can be specified in
any order, but all must precede the pathname or special_file.
Options without parameters can be listed individually or grouped
together. Options with parameters must be listed individually, but
white space between the option and its parameter is discretionary.
Normally, provides only fatal error messages which are
directed to standard error. The (verbose)
option sends device-specific information
related to low-level operation of to stan‐
dard output (stdout). This option is most
useful to trained service personnel because
it usually requires detailed knowledge of
device operation before the information can
be interpreted correctly.
(re-certify) This option forces a complete tape certifi‐
cation whether or not the tape has been cer‐
tified previously. All record of any previ‐
ously spared blocks is discarded, so any bad
blocks will have to be rediscovered. This
option should be used only if:
· It is suspected that numerous blocks on
the tape have been spared which should
not have been, or
· It is necessary to destroy (overwrite)
all previous data on the tape.
The format option is a device-specific number in the range
through It is intended solely for use with
certain SS/80 devices that support multiple
media formats (independent from interleave
factor). For example, certain microfloppy
drives support 256-, 512-, and 1024-byte
sectors. passes any supplied format option
directly through to the device. The device
then either accepts the format option if it
is supported, or rejects it if it is not
supported. Refer to device operating manu‐
als for additional information. The default
format option is
The interleave factor,
interleave, refers to the relationship
between sequential logical records and
sequential physical records. It defines the
number of physical records on the media that
lie between the beginning points of two con‐
secutively numbered logical records. The
choice of interleave factor can have a sub‐
stantial impact on disk performance.
Partition DDS cartridge media into two logical sepa‐
rate volumes: partition 0 and partition 1:
· size specifies the minimum size of parti‐
tion 1 (in megabytes). The maximum
allowed value is 1200 megabytes.
· Partition 0 is the remainder of the tape
(partition 0 physically follows partition
1 on the tape).
The actual size of partition 1 is somewhat
larger than the requested size to allow for
tape media errors during writing. Thus, a
size of 400 megabytes formats the DDS tape
into two partitions where partition 1 holds
at least 400 megabytes of data, and the
remainder of the tape is used for partition
0 (for a 1300 megabytes DDS cartridge, this
means that partition 0 has a size somewhat
less than 900 megabytes).
Note that it is unnecessary to format a DDS
tape before use unless the tape is being
partitioned. Unformatted DDS media does not
require initialization when used as a single
partition tape. Accessing partition 1 on a
single-partition tape produces an error. To
change a two-partition tape to single-parti‐
tion, use with specified as the size.
pathname pathname is the path name to the character
(raw) device special file associated with
the device unit or volume that is to be ini‐
tialized. aborts if you lack either read or
write permission to the device special file,
or if the device is currently open for any
other process. This prevents accidental
initialization of the root device or any
mounted volume. locks the unit or volume
being initialized so that no other processes
can access it.
Except for SCSI devices, pathname must be a
device special file whose minor number of
the device being initialized has the diag‐
nostic bit set. For device special files
with the diagnostic bit set, the section
number is meaningless. The entire device is
accessed.
The scrub_character refers to the character
input by the user. The disk will be
scrubbed using this character. Any charac‐
ter between or or can be specified. The
option must be used with the option.
If the option is specified, the disk will be
scrubbed for scrub_count number of times.
This option must be used with the option.
This option is used for disk scrubbing.
The and options must be used with the
option. If both and options are not speci‐
fied, then the device will be scrubbed three
times.
special_file The special_file is path name of the charac‐
ter (raw) device special file associated
with the device that is to be scrubbed.
aborts if you do not have either read or
write permission to the device special file,
or if the device is currently open for any
other process. locks the device special
file being scrubbed so that no other pro‐
cesses can access it.
Note that before a device special file is
scrubbed, if any file system is on the disk,
you must unmount the file system.
This option is used to verify the scrubbed disk.
The option randomly validates the scrubbed
data written during the last pass of the
disk scrub process. The option must be used
with the option.
When a given unit contains multiple volumes as defined by the drive
controller, any available unit or volume associated with that con‐
troller can be initialized, independent of other units and volumes that
share the same controller. Thus, you can initialize one unit or volume
to any format or interleave factor without affecting formats or data on
companion units or volumes. However, be aware that the entire unit or
volume (as defined by the drive controller) is initialized without con‐
sidering the possibility that it may be subdivided into smaller struc‐
tures by the the operating software. When such structures exist, unex‐
pected loss of data is possible.
dominates controller resources and limits access by competing processes
to other units or volumes sharing the same controller. If other simul‐
taneous processes need access to the same controller, some access
degradation can be expected until initialization is complete; espe‐
cially if you are initializing a tape cartridge in a drive that shares
the root disk controller.
In general, attempts to carefully check any (format option) or (inter‐
leave options) supplied, and aborts if an option is out of range or
inappropriate for the media being initialized. Specifying an inter‐
leave factor or format option value of has the same effect as not spec‐
ifying the option at all.
For disks that support interleave factors, the acceptable range is usu‐
ally (no interleave) through n−1, where n is the number of sectors per
track. Refer to the appropriate device operating manual for recom‐
mended values.
If a disk being initialized requires an interleave factor but none is
specified, provides an appropriate, though not necessarily optimum
default.
When a given device supports format options, the allowable range of
interleave factors may be related to the specified format option. In
such instances, cannot check the interleave factor if one is specified.
Notes
Most types of mass storage media must be initialized before they can be
used. HP hard disks, flexible disks, and cartridge tapes require some
form of initialization, but 9-track tapes do not. Initialization usu‐
ally involves formatting the media, writing and reading test patterns,
then sparing any defective blocks. Depending upon the media and device
type, none, some, or all of the initialization process may have been
performed at the factory. completes whatever steps are appropriate to
prepare the media for error-free operation.
Most HP hard disks are formatted and exhaustively tested at the factory
by use of a process more thorough but also more time-consuming than
appropriate for However, is still valuable for ensuring the integrity
of the media after factory shipment, formatting with the correct inter‐
leave factor, and sparing any blocks which may have become defective
since original factory testing was performed.
HP flexible disks are not usually formatted prior to shipment, so they
must undergo the entire initialization process before they can be used.
When a tape is certified, it is thoroughly tested and defective blocks
are spared. usually certifies a tape only if it has not been certified
previously. If the tape has been previously certified and spared, usu‐
ally reorganizes the tape's spare block table, retaining any previous
spares, and optimizing their assignment for maximum performance under
sequential access. Reorganizing the spare block table takes only a few
seconds, whereas complete certification takes about a half-hour for
150-foot tapes, and over an hour for 600-foot tapes.
Reorganization of a tape's spare block table technically renders any
existing data undefined, but the data is not usually destroyed by over‐
writing. To ensure that old tape data is destroyed, which is useful
for security, complete tape re-certification can be forced with the
option.
Some applications may require that a file system be placed on the media
before use. does not create a file system; it only prepares media for
writing and reading. If such a file system is required, other utili‐
ties such as or must be invoked after running (see newfs(1M),
lifinit(1), and mkfs(1M)).
RETURN VALUE
returns one of the following values:
0 Successful completion.
1 A device-related error occurred.
2 A syntax-related error was encountered.
ERRORS
Appropriate error messages are printed on standard error during execu‐
tion of
EXAMPLES
Scrub the specified device special file using the default of three
times (the default).
Scrub the specified device special file twice with a scrub character of
0.
Scrub the specified device special file twice with a scrub character of
0 and verify.
WARNINGS
For a device that contains multiple units on a single controller, each
unit can be initialized independently from any other unit. It should
be noted, however, that requires that there be no other processes
accessing the device before initialization begins, regardless of which
unit is being initialized. If there are accesses currently in
progress, aborts.
Aborting is likely to leave the medium in a corrupt state, even if it
was previously initialized. To recover, the initialization must be
restarted.
During the initialization process, rejects all other accesses to the
device being initialized, producing the error (see open(2)).
DEPENDENCIES
Series 800
Partitioning of DDS tape media option) is not supported.
AUTHOR
was developed by HP.
SEE ALSOlifinit(1), mkfs(1M), newfs(1M), open(2).
mediainit(1)
