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HP OpenVMS DCL Dictionary

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Defines for disk volumes the default protection to be applied to all files on the volume.

Specify the code according to the standard syntax rules described in the HP OpenVMS Guide to System Security. Any attributes not specified are taken from the current default protection.

Note that this attribute is not used when the volume is being used on an OpenVMS system, but is provided to control the process's use of the volume on RSX-11M systems. OpenVMS systems always use the default file protection. Use the SET PROTECTION/DEFAULT command to change the default file protection.


Used in conjunction with the /NOSHARE qualifier to create a group volume. The group volume allows access by system (S), owner (O), and group (G) accessors. The protection is (S:RWCD,O:RWCD,G:RWCD,W).

The owner user identification code (UIC) of the volume defaults to your group number and a member number of 0.


Specifies, for disk volumes, the number of file headers to be allocated for the index file. The minimum and default value is 16. The maximum is the value set with the /MAXIMUM_FILES qualifier.

This qualifier is useful when you want to create a number of files and want to streamline the process of allocating space for that number of file headers. If you do not specify this qualifier, the file system dynamically allocates space as it is needed for new headers on the volume.


The default value for the /HEADERS qualifier is generally insufficient for ODS-2 and ODS-5 disks. To improve performance and avoid SYSTEM-F-HEADERFULL errors, HP recommends that you set this value to be approximately the number of files that you anticipate having on your disk; however, grossly overestimating this value will result in wasted disk space.

The /HEADERS qualifier controls how much space is initially allocated to INDEXF.SYS for headers. Each file on a disk requires at least one file header and each header occupies one block within INDEXF.SYS. Files that have many Access Control Entries (ACE) or are very fragmented may use more than one header.

The default value of 16 leaves room for less than 10 files to be created before INDEXF.SYS must extend; therefore, try to estimate the total number of files that will be created on the disk and specify it here. This will improve disk access performance. Overestimating the value may lead to wasted disk space. This value cannot be changed without reinitializing the volume.

INDEXF.SYS is limited as to how many times it may extend. When the map area in its header (where the retrieval pointers are stored) becomes full, file creation fails with the message "SYSTEM-W-HEADERFULL."

/HIGHWATER (default)


Applies to Files-11 On-Disk Structure Level 2 (ODS-2) and Level 5 (ODS-5) disks only.

Sets the file high-water mark (FHM) volume attribute, which guarantees that users cannot read data that they have not written. You cannot specify the /NOHIGHWATER qualifier for magnetic tape.

The /NOHIGHWATER qualifier disables FHM for a disk volume.


Applies to Files-11 On-Disk Structure Level 2 (ODS-2) and Level 5 (ODS-5) disks only.

Specifies where the volume's homeblock and spare copy of the homeblock are placed on disk. The value of option can be one of the following:

    Causes the homeblocks to be placed at separate locations on disk, to protect against failure of a disk block. Placement depends on the reported geometry of the disk.
  • FIXED (default)
    Causes the homeblocks to be placed at separate fixed locations on the disk. Placement is independent of the reported geometry of the disk. This caters to disks that report different geometries according to which type of controller they are attached to.
    Causes the homeblocks to be placed contiguously at the start of the disk. When used with the /INDEX=BEGINNING qualifier, this setting allows container file systems to maximize the amount of contiguous space on the disk, for example, to hold one large file, such as a database.


Specifies the location of the index file for the volume's directory structure. Possible positions are as follows:
BEGINNING Beginning of the volume
MIDDLE Middle of the volume (default)
END End of the volume
BLOCK: n Beginning of the logical block specified by n


Specifies that the magnetic tape will be used for interchange in a heterogeneous vendor environment. The /INTERCHANGE qualifier omits the ANSI VOL2 labels. Under OpenVMS, the ANSI VOL2 labels contain OpenVMS specific security attributes.

For more information on the /INTERCHANGE qualifier and on magnetic tape labeling and tape interchange, refer to the HP OpenVMS System Manager's Manual, Volume 1: Essentials.


Defines characteristics for the magnetic tape volume label, as directed by the included option. The available options are as follows:
  • OWNER_IDENTIFIER:"(14 ANSI characters)"
    Allows you to specify the Owner Identifier field in the volume label. The field specified can accept up to 14 ANSI characters.
    Specifies the character to be written in the volume accessibility field of the OpenVMS ANSI volume label VOL1 on an ANSI magnetic tape. The character may be any valid ANSI "a" character. This set of characters includes numeric characters, uppercase letters, and any one of the following nonalphanumeric characters:

    ! " % ' ( ) * + , - . / : ; < = > ?

    By default, the OpenVMS operating system provides a routine that checks this field in the following manner:
    • If the magnetic tape was created on a version of the OpenVMS operating system that conforms to Version 3 of ANSI, then this option must be used to override any character other than an ASCII space.
    • If a protection is specified and the magnetic tape conforms to an ANSI standard that is later than Version 3, then this option must be used to override any character other than an ASCII 1.

    If you specify any character other than the default, you must specify the /OVERRIDE=ACCESSIBILITY qualifier on the INITIALIZE and MOUNT commands in order to access the magnetic tape.


Specifies that the volume should be initialized with volume expansion. n defines the maximum growth potential of the volume in blocks. If no value is specified, the maximum expansion potential is set up.

The maximum value depends on the value specified for /CLUSTER_SIZE. If /CLUSTER_SIZE is 8 (the default when /LIMIT is specified) or more, 1TB of expansion is set up. If the value for /CLUSTER_SIZE is less than 8, the expansion limit is set to 65535*4096*Cluster_value because the maximum size of the bitmap is 65535 blocks. For more information about volume expansion, refer to the HP Volume Shadowing for OpenVMS manual.

The minimum allowed value is the largest of the following values:

  • The value supplied with /LIMIT
  • The physical disk size
  • The size resulting from a 256-block BITMAP.SYS file (that is, 256 * 4096 bits/block * Disk Cluster Value)

If a value less than the minimum is supplied, the value is increased to the minimum. This value is displayed (in blocks) as the "Expansion Size Limit" in the output from a SHOW DEVICE/FULL command.


If you specify /LIMIT and do not specify a value for /CLUSTER_SIZE, a value of /CLUSTER_SIZE=8 is used.


Restricts the maximum number of files that the volume can contain. The /MAXIMUM_FILES qualifier overrides the default value, which is calculated as follows:

(volume size in blocks)/((cluster factor + 1) * 2)

The maximum size you can specify for any volume is as follows:

(volume size in blocks)/(cluster factor + 1)

The minimum value is 0. Note that the maximum can be increased only by reinitializing the volume.


The /MAXIMUM_FILES qualifier does not reserve or create space for new file headers on a volume. The file system dynamically allocates space as it is needed for new headers.


Controls whether data records are automatically compacted and blocked together on any device that supports data compaction. Data compaction and record blocking increase the amount of data that can be stored on a single tape cartridge.

Note that once data compaction or noncompaction has been selected for a given cartridge, that same status applies to the entire cartridge.

VAX Restriction

For SCSI tapes, compaction works only when the tape is connected using a local SCSI bus; compaction does not work if the VAX is a TMSCP client or if the tape resides in an HSJ controller.


Requests the INITIALIZE command to ignore data on a magnetic tape volume that protects it from being overwritten. You can specify one or more of the following options:
ACCESSIBILITY (For magnetic tapes only.) If the installation allows, this option overrides any character in the Accessibility field of the volume. The necessity of this option is defined by the installation. That is, each installation has the option of specifying a routine that the magnetic tape file system will use to process this field. By default, OpenVMS provides a routine that checks this field in the following manner. If the magnetic tape was created on a version of OpenVMS that conforms to Version 3 of ANSI, this option must be used to override any character other than an ASCII space. If a protection is specified and the magnetic tape conforms to an ANSI standard that is higher than Version 3, this option must be used to override any character other than an ASCII 1. To use the ACCESSIBILITY option, you must have the user privilege VOLPRO or be the owner of the volume.
EXPIRATION (For magnetic tapes only.) Allows you to write to a tape that has not yet reached its expiration date. You may need to do this for magnetic tapes that were created before VAX/VMS Version 4.0 on Digital operating systems using the D% format in the volume Owner Identifier field. You must have the user privilege VOLPRO to override volume protection, or your UIC must match the UIC written on the volume.
OWNER_IDENTIFIER Allows you to override the processing of the Owner Identifier field of the volume label.

If you specify only one option, you can omit the parentheses.

To initialize a volume that was initialized previously with the /PROTECTION qualifier, your UIC must match the UIC written on the volume or you must have VOLPRO privilege.

You can initialize a volume previously initialized with /PROTECTION if you have control access.


Specifies an owner user identification code (UIC) for the volume. The default is your default UIC. Specify the UIC using standard UIC format as described in the HP OpenVMS Guide to System Security.

For magnetic tapes, no UIC is written unless protection on the magnetic tape is specified. If protection is specified, but no owner UIC is specified, your current UIC is assigned ownership of the volume.


Applies the specified protection to the volume:

  • Specify the ownership parameter as system (S), owner (O), group (G), or world (W).
  • Specify the access parameter as read (R), write (W), create (C), or delete (D).

The default is your default protection. Note that the /GROUP, /SHARE, and /SYSTEM qualifiers can also be used to define protection for disk volumes.

For magnetic tape, the protection code is written to an OpenVMS specific volume label. The system applies only read (R) and write (W) access restrictions; create and delete (D) access are meaningless. Moreover, the system and the owner are always given both read (R) and write (W) access to magnetic tapes, regardless of the protection code you specify.

For more information on specifying protection code, refer to the HP OpenVMS Guide to System Security. Any attributes not specified are taken from the current default protection.

When you specify a protection code for an entire disk volume, the access type E (execute) indicates create access.

/SHADOW=(device_name_1, device_name_2, device_name_3) label (Alpha only)

Initializes multiple members of a future shadow set. Initializing multiple members in this way eliminates the requirement of a full copy when you later create a shadow set.

When both the /SHADOW and /ERASE qualifiers are specified, the INITIALIZE command performs the following operations:

  • Formats up to six devices with one command, so that any three can be subsequently mounted together as members of a new host-based shadow set
  • Writes a label on each volume
  • Deletes all information from the devices except for the system files and leaves each device with identical file structure information. All former contents of the disks are lost.

HP strongly recommends that you use the /ERASE qualifier. When /ERASE is specified, a merge operation is substantially reduced. However, using /ERASE has two side effects that are important considerations for volume shadowing: the setting of the ERASE volume attribute and the time it takes to initialize a volume using /ERASE.

If /ERASE is specified with /SHADOW, the disks are erased sequentially, which effectively doubles or triples the time it takes for the command to complete. If the disks are large, consider performing multiple, simultaneous INITIALIZE/ERASE commands (without /SHADOW) to erase the disks. Once all of those commands have completed, then execute an INITIALIZE/SHADOW command (without /ERASE).

Once you have initialized your devices using /ERASE and /SHADOW, you can then mount up to three of these devices as members of a new host-based shadow set.

Note that the INITIALIZE/SHADOW command should not be used to initialize a disk to be added to an existing shadow set, as no benefit is gained.

For more information about volume shadowing, refer to the HP Volume Shadowing for OpenVMS manual.

/SHARE (default)


Permits all categories of access by all categories of ownership. The /NOSHARE qualifier denies access to group (unless the /GROUP qualifier is also specified) and world processes.


When /SIZE=n is specified for a magnetic disk, n specifies the size (in blocks) of the logical volume (the space available for the file system). This allows you to INITIALIZE a disk with a file system size that is less than the physical volume size, which can be useful if you plan to create a shadow set using this disk and a smaller physical disk. The value of n is displayed (in blocks) as "Logical Volume Size" in the output from a SHOW DEVICE/FULL command.

For DECram disks, /SIZE specifies the size (in blocks) of the disk (device type DT$_RAM_DISK) to be allocated from available memory. The size of the device is created at disk initialization time.

To deallocate space, specify /SIZE=0. All resources specifically allocated to the DECram disk are returned to the system.

Note that n cannot exceed 524,280 blocks either on a VAX system or on versions of DECram prior to Version 2.3. DECram Version 2.3 running on an Alpha system supports up to 67,108,864 blocks, equivalent to 32GB.


Specifies whether the volume should be formatted in Files-11 On-Disk Structure Level 1, 2 (the default), or 5.

Structure Level 1 is incompatible with the /DATA_CHECK and /CLUSTER_SIZE qualifiers. The default protection for a Structure Level 1 disk is full access to system, owner, and group, and read (R) access to all other users.

Note that Alpha does not support Files-11 On-Disk Structure Level 1 disks, and specifying 1 on Alpha results in an error. VAX does not support Structure Level 5 disks, and specifying 5 on VAX results in an error.

Refer to the HP OpenVMS System Manager's Manual, Volume 1: Essentials for more information about Structure Level 5 (ODS-5) disks.


Requires a system UIC or SYSPRV (system privilege) privilege.

Defines a system volume. The owner UIC defaults to [1,1]. Protection defaults to complete access by all ownership categories, except that only system processes can create top-level directories.


Specifies a user name to be associated with the volume. The name must be 1 to 12 alphanumeric characters. The default is your user name.



Indicates whether the disk has bad block data on it. Use the /NOVERIFIED qualifier to ignore bad block data on the disk. The default is the /VERIFIED qualifier for disks with 4096 blocks or more and the /NOVERIFIED qualifier for disks with less than 4096 blocks.


Applies to Files-11 ODS-5 volumes only.

Enables or disables hardlinks and automatic updates of access dates on ODS-5 volumes.

The default value for delta-time is 1 second, chosen to comply with the "seconds since EPOCH" time interface required by POSIX st_atime . A site can choose a larger delta time to reduce overhead if 1-second granularity is not required.

Note that the NOACCESS_DATES option affects only the node on which the command is issued. Other nodes are not affected by the change until the next time the volume is mounted.

Refer to the Guide to OpenVMS File Applications for additional information.


Specifies the number of mapping pointers (used to access data in the file) to be allocated for file windows. The value can be an integer in the range of 7 to 80. The default is 7.




Initializes the volume on $FLOPPY1, labels the volume ACCOUNTS, and gives the volume a user name of CPA.




This sequence of commands shows how to initialize an RK06/RK07 volume. First, the device is allocated, to ensure that no one else can access it. Then, when the volume is physically mounted on the device, the INITIALIZE command initializes it. When the volume is initialized, the MOUNT command makes the file structure available. Before you can place any files on the volume, you must create a directory, as shown by the CREATE/DIRECTORY command.




These commands show the procedure necessary to initialize a magnetic tape. After allocating a drive, the magnetic tape is loaded on the device, and the INITIALIZE command writes the label SOURCE on it. Then, the MOUNT command mounts the magnetic tape so that files can be written on it.




This example creates a BACKUP tape with compaction and record blocking disabled.




DEVICE              DEVICE          ERROR    VOLUME         FREE  TRANS MNT
 NAME               STATUS          COUNT     LABEL        BLOCKS COUNT CNT
DSA42:              MOUNTED             0  NONVOLATILE    5799600     1   1


This example shows correct use of the INITIALIZE/ERASE/SHADOW command. Note that the command specifies multiple devices on the same line.


Creates or initializes queues. You use this command to create queues and to assign them names and options. The /BATCH qualifier is required to create a batch queue.

Requires OPER (operator) privilege to create queues and manage (M) access to modify queues.


INITIALIZE/QUEUE queue-name[:]



Specifies the name of an execution queue or a generic queue. The queue name may be a string of 1 to 31 characters. The character string can include any uppercase and lowercase letters, digits, the dollar sign ($), and the underscore (_), and must include at least one alphabetic character.


Use the INITIALIZE/QUEUE command to create a queue or to change the options of an existing queue that is stopped.

Normally you create output and batch queues by entering the necessary INITIALIZE/QUEUE commands when you set up your system or OpenVMS Cluster. Later, you can use the INITIALIZE/QUEUE command to create additional queues as they are needed. When you create a queue with the INITIALIZE/QUEUE command, information about the queue is stored in the queue database.

To create and start the queue at the same time, you can use the INITIALIZE/QUEUE/START command. If you want to create the queue only and start it at another time, you can enter only the INITIALIZE/QUEUE command. Later you can enter the START/QUEUE command to begin queue operations.

You can use the INITIALIZE/QUEUE, START/QUEUE, and SET QUEUE commands to change queue options; as you change queue options, information about the queue in the queue database is updated.

You can use the INITIALIZE and START commands only on stopped queues. To change options on a running queue, use the SET QUEUE command. To change queue options that cannot be altered with the SET QUEUE command, use the following procedure:

  1. Stop the queue with the STOP/QUEUE/NEXT command.
  2. Restart the queue with the START/QUEUE or the INITIALIZE/QUEUE/START command, specifying the appropriate qualifiers for the options you desire.
    Any qualifiers that you do not specify remain as they were when the queue was previously initialized, started, or set.

Note that initializing an existing queue does not delete any current jobs in that queue. Any new queue settings established by the new INITIALIZE/QUEUE command affect all jobs waiting in the queue or subsequently entering the queue. Any jobs that are executing in the queue when it is stopped complete their execution under the old settings.

The following qualifiers apply to generic and execution queues:


The following qualifiers apply to all types of execution queues:


The following qualifiers apply only to batch execution queues:


The following qualifiers apply only to printer, terminal, or server execution queues:


Types of Queues

There are several different types of queues. In general, queues can be divided into two major classes: generic and execution. When a job is sent to an execution queue, it is executed in that queue. No processing takes place in generic queues. Generic queues hold jobs that will execute on an execution queue.

Generic Queues

The following are several types of generic queues:

  • Generic batch queue---Holds batch jobs for execution on batch execution queues.
  • Generic output queue---Holds jobs for execution on output queues. There are three types of generic output queues:
    • Generic printer queue---Holds print jobs for printing on output execution queues.
    • Generic server queue---Holds jobs for processing on output execution queues.
    • Generic terminal queue---Holds print jobs for printing on output execution queues.

The /GENERIC qualifier designates a queue as a generic queue. You specify the execution queues to which a generic queue feeds jobs in one of two ways:

  • You can explicitly name execution queues assigned to the generic queue by including a list of queues with the /GENERIC qualifier.
  • You can specify the execution queues that may receive jobs from any generic queue that does not specify an explicit target list by specifying the /ENABLE=GENERIC qualifier when you create the execution queue.

Generic queues, unlike execution queues, are not automatically stopped when the system is shut down or the queue manager is stopped; therefore, generic queues do not normally need to be restarted each time the system reboots.

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