The default format for disk volumes in the OpenVMS operating
    system is called the Files-11 On-Disk Structure Level 2. The
    default for magnetic tape volumes is based on Level 3 of the
    ANSI standard for magnetic tape labels and file structure for
    informational interchange (ANSI X3.27-1978).

    The INITIALIZE command can also initialize disk volumes in the
    Files-11 On-Disk Structure Level 1 format.

    You must have VOLPRO privilege to initialize a volume, except in
    the following cases:

    o  A blank disk or magnetic tape volume; that is, a volume that
       has never been written

    o  A disk volume that is owned by your current user
       identification code (UIC) or by the UIC [0,0]

    o  A magnetic tape volume that allows write (W)  access to your
       current UIC that was not protected when it was initialized

    After the volume is initialized and mounted, the SET SECURITY
    command may be used to modify the security profile. When you
    initialize a disk volume, the caching attribute of its root
    directory (000000.DIR;1) is set to write-through. This means
    that by default, all the files and directories that you create in
    the volume will inherit a caching attribute of write-through. To
    change the caching attribute, use the SET FILE command with the
    /CACHING_ATTRIBUTE qualifier.

    When the INITIALIZE command initializes a magnetic tape volume,
    it always attempts to read the volume. A blank magnetic tape can
    sometimes cause unrecoverable errors, such as the following:

    o  An invalid volume number error message:

       %INIT-F-VOLINV, volume is invalid

    o  A runaway magnetic tape (this frequently occurs with new
       magnetic tapes that have never been written or that have
       been run through verifying machines). You can stop a runaway
       magnetic tape only by setting the magnetic tape drive off line
       and by then putting it back on line.

    If this type of unrecoverable error occurs, you can initialize
    a magnetic tape successfully by repeating the INITIALIZE command
    from an account that has VOLPRO (volume protection) privilege and
    by specifying the following qualifier in the command:

    /OVERRIDE=(ACCESSIBILITY,EXPIRATION)

    This qualifier ensures that the INITIALIZE command does not
    attempt to verify any labels on the magnetic tape.

    If you have VOLPRO privilege, the INITIALIZE command initializes
    a disk without reading the ownership information. If you do
    not have VOLPRO privilege, the INITIALIZE command checks the
    ownership of the volume before initializing the disk. A blank
    disk or a disk with an incorrect format can sometimes cause a
    fatal drive error. If a blank disk or a disk with an incorrect
    format causes this type of error, you can initialize a disk
    successfully by repeating the INITIALIZE command with the
    /DENSITY qualifier from an account that has VOLPRO privilege.

    Many of the INITIALIZE command qualifiers allow you to specify
    parameters that can maximize input/output (I/O) efficiency.