unixdev.net


Switch to SpeakEasy.net DSL

The Modular Manual Browser

Home Page
Manual: (HP-UX-11.11)
Page:
Section:
Apropos / Subsearch:
optional field



 mediainit(1)							mediainit(1)




 NAME
      mediainit - initialize disk or partition DDS tape

 SYNOPSIS
      mediainit [-vr] [-f fmt_optn] [-i interleave] [-p size] pathname

 DESCRIPTION
      mediainit 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.

      mediainit can also used for partitioning DDS tape media.	See the -p
      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.	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.

	   -v		  Normally, mediainit provides only fatal error
			  messages which are directed to standard error.
			  The -v (verbose) option sends device-specific
			  information related to low-level operation of
			  mediainit to standard 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.

	   -r		  (re-certify) This option forces a complete tape
			  certification whether or not the tape has been
			  certified previously.	 All record of any
			  previously 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.

	   -f fmt_optn	  The format option is a device-specific number in
			  the range 0 through 239.  It is intended solely
			  for use with certain SS/80 devices that support
			  multiple media formats (independent from



 Hewlett-Packard Company	    - 1 -   HP-UX Release 11i: November 2000






 mediainit(1)							mediainit(1)




			  interleave factor).  For example, certain
			  microfloppy drives support 256-, 512-, and 1024-
			  byte sectors.	 mediainit 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 manuals for
			  additional information.  The default format option
			  is 0.

	   -i interleave  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 consecutively
			  numbered logical records.  The choice of
			  interleave factor can have a substantial impact on
			  disk performance.

	   -p size	  Partition DDS cartridge media into two logical
			  separate volumes: partition 0 and partition 1:

			       +  size specifies the minimum size of
				  partition 1 (in Mbytes).  The maximum
				  allowed value is 1200.

			       +  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
			  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 Mbyte DDS cartridge, this
			  means that partition 0 has a size somewhat less
			  than 900 Mbytes).

			  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-partition, use mediainit with 0
			  specified as the size.

	   pathname	  pathname is the path name to the character (raw)
			  device special file associated with the device



 Hewlett-Packard Company	    - 2 -   HP-UX Release 11i: November 2000






 mediainit(1)							mediainit(1)




			  unit or volume that is to be initialized.
			  mediainit 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.  mediainit
			  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 diagnostic bit set.	 For
			  device special files with the diagnostic bit set,
			  the section number is meaningless.  The entire
			  device is accessed.

      When a given unit contains multiple volumes as defined by the drive
      controller, any available unit or volume associated with that
      controller 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 considering the possibility that it may be subdivided into
      smaller structures by the the operating software.	 When such
      structures exist, unexpected loss of data is possible.

      mediainit dominates controller resources and limits access by
      competing processes to other units or volumes sharing the same
      controller.  If other simultaneous processes need access to the same
      controller, some access degradation can be expected until
      initialization is complete; especially if you are initializing a tape
      cartridge in a drive that shares the root disk controller.

      In general, mediainit attempts to carefully check any -f (format
      option) or -i (interleave options) supplied, and aborts if an option
      is out of range or inappropriate for the media being initialized.
      Specifying an interleave factor or format option value of 0 has the
      same effect as not specifying the option at all.

      For disks that support interleave factors, the acceptable range is
      usually 1 (no interleave) through n-1, where n is the number of
      sectors per track.  Refer to the appropriate device operating manual
      for recommended values.

      If a disk being initialized requires an interleave factor but none is
      specified, mediainit 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



 Hewlett-Packard Company	    - 3 -   HP-UX Release 11i: November 2000






 mediainit(1)							mediainit(1)




      such instances, mediainit 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
      usually 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.  mediainit 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 mediainit.  However, mediainit is still valuable
      for ensuring the integrity of the media after factory shipment,
      formatting with the correct interleave 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.  mediainit usually certifies a tape only if it has not
      been certified previously.  If the tape has been previously certified
      and spared, mediainit usually 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
      overwriting.  To ensure that old tape data is destroyed, which is
      useful for security, complete tape re-certification can be forced with
      the -r option.

      Some applications may require that a file system be placed on the
      media before use.	 mediainit does not create a file system; it only
      prepares media for writing and reading.  If such a file system is
      required, other utilities such as newfs, lifinit, or mkfs must be
      invoked after running mediainit (see newfs(1M), lifinit(1), and
      mkfs(1M)).

 RETURN VALUE
      mediainit returns one of the following values:




 Hewlett-Packard Company	    - 4 -   HP-UX Release 11i: November 2000






 mediainit(1)							mediainit(1)




	   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
      execution of mediainit.

 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 mediainit 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, mediainit aborts.

      Aborting mediainit 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, open() rejects all other accesses
      to the device being initialized, producing the error EACCES (see
      open(2)).

 DEPENDENCIES
    Series 800
      Partitioning of DDS tape media (-p option) is not supported.

 AUTHOR
      mediainit was developed by HP.

 SEE ALSO
      lifinit(1), mkfs(1M), newfs(1M).





















 Hewlett-Packard Company	    - 5 -   HP-UX Release 11i: November 2000