Document revision date: 30 March 2001

## OpenVMS System Services Reference Manual

Previous | Contents | Index

Unless you specify MNT$M_GROUP or MNT$M_SYSTEM, the logical name is entered in the process logical name table.

#### MNT$_OWNER

Specifies the UIC to be assigned ownership of the volume. The buffer must contain a longword octal value, which is the UIC. If the volume is Files-11 structured, the specified value overrides the ownership recorded on the volume. You need either VOLPRO privilege or ownership of the volume to assign a UIC to a Files-11 structured volume.

#### MNT$_PROCESSOR

For magnetic tapes and Files-11 On-Disk Structure Level 1 disks, MNT$_PROCESSOR specifies the name of the ancillary control process (ACP) that is to process the volume. The specified ACP overrides the default ACP associated with the device.

For Files-11 On-Disk Structure Level 2 disks, MNT$_PROCESSOR controls block cache allocation.

To specify MNT$_PROCESSOR, the caller must have OPER privilege.

The buffer must contain a character string specifying either the string UNIQUE, a device name, or a file specification. Following is a description of the action taken for each of these cases:

String | Description
--- | ---
UNIQUE | For magnetic tapes and Files-11 Structure Level 1 disks, UNIQUE specifies that $MOUNT create a new process to execute a copy of the default ACP image associated with the device specified by the MNT$_DEVNAM item code. For Files-11 Structure Level 2 disks, UNIQUE allocates a separate block cache.
ddcu | For magnetic tapes and Files-11 Structure Level 1 disks, ddcu specifies that $MOUNT use the ACP process currently being used by the device ddcu. The device specified must be in the format ddcu, for example, DRA3. For Files-11 Structure Level 1 disks, ddcu specifies that $MOUNT take the block allocation from the specified device.
filespec | Specifies that $MOUNT create a new process to execute the ACP image with the file specification filespec. Wildcard characters are not allowed in the file specification. The file must be in the disk and directory specified by the logical name SYS$SYSTEM. This operation requires CMKRNL privilege.

#### MNT$_QUOTA

Specifies the size of the quota record cache in units of quota records. The buffer must contain a longword value, which is this size. To specify MNT$_QUOTA, you need OPER privilege. The value 0 disables caching. The MNT$_QUOTA item code applies only to disks.

#### MNT$_RECORDSIZ

Specifies the number of characters in each record and is used with MNT$_BLOCKSIZE to specify the data formats for foreign volumes. The buffer must contain a longword value less than or equal to the block size. The MNT$_RECORDSIZ item code applies only to tapes.

If you do not specify MNT$_RECORDSIZ, the record size is assumed to be equal to the block size.

#### MNT$_SHAMEM

Specifies the name of a physical device to be mounted into a shadow set. The MNT$_SHAMEM descriptor is a 1- to 64-character string containing the device name. The string can be a physical device name or a logical name; if it is a logical name, it must translate to a physical device name. An item list must contain at least one item descriptor specifying a member; this item descriptor must appear after the MNT$_SHANAM item descriptor.

Volume Shadowing for OpenVMS automatically performs a copy or a merge operation, if necessary, when it mounts the disk into the shadow set.

#### MNT$_SHANAM

Specifies the name of the virtual unit to be mounted. The buffer is a 1- to 64-character string containing the device name. The virtual unit name can be a logical name; if it is a logical name, it must translate to a virtual unit name.

Because every shadow set is represented by a virtual unit, you must include at least one MNT$_SHANAM item descriptor in the item list that you pass to $MOUNT to create and mount the shadow set. If you are mounting a volume set containing more than one shadow set, you must include one MNT$_SHANAM item descriptor for each virtual unit included in the volume set.

The relative position of the item descriptors in the item list determines the membership of the shadow set. That is, it indicates which members should be bound to a specific virtual unit to form the shadow set. You must first specify the virtual unit by using the MNT$_SHANAM item code. Then, you can specify any number of members that are to be represented by that virtual unit by using one of the following item codes: MNT$_SHAMEM, MNT$_SHAMEM_COPY, or MNT$_SHAMEM_MGCOPY. If you specify one shadow set and want to specify a second, specify a second virtual unit item descriptor. The members you specify subsequently are bound to the shadow set represented by the virtual unit specified in the second virtual unit item descriptor.

#### MNT$_UCS

Specifies a descriptor containing a Universal Character Sequence (UCS) defined by ISO 2022 and used when mounting an ISO 9660 CD-ROM. For more information, refer to the OpenVMS System Manager's Manual.

#### MNT$_UNDEFINED_FAT

Specifies the default file attributes to be used for the records on ISO 9660 media for which no record format has been specified.

The buffer contains a 32-bit structure that defines a file's record format, record attributes, and maximum record size.

The following diagram depicts the structure of the Undefined File Attributes buffer:

The following table defines the buffer fields:

Buffer Field | Definition
--- | ---
UNFAT$W_MRS | Maximum record size; specifies the maximum record size for all records in a file: 0 to 32767. Applies only to FIXED or STREAM formats.
UNFAT$B_RAT | Record attributes; specifies the attributes for all records in a file: NONE, CR, FTN, PRN, NOBKS. Applies only to non-STREAM record formats.
UNFAT$B_RFM | Record format; specifies the format for all records in a file: FIXED, VARIABLE, STREAM, STREAM_LF, STREAM_CR, LSB_VARIABLE, or MST_VARIABLE.

#### MNT$_VOLNAM

Specifies the name of the volume to be mounted on the device. The number of characters allowed in a volume name depends on the type of device, as follows:

Device Type | Number of Characters in Label
--- | ---
Magnetic tape | 0--6
Files-11 disk | 1--12
ISO 9660 disk | 1--32

The operating system requires disk volume labels to be unique in the first 12 characters within a given domain.

The MNT$_VOLNAM item code can appear more than once in an item list; it appears more than once when a volume set is being mounted because, in this case, one volume name is given to each volume in the volume set.

When a disk volume set is being mounted, you must specify MNT$_DEVNAM and MNT$_VOLNAM once for each volume of the volume set. The $MOUNT service mounts the volume specified by the first MNT$_VOLNAM item code on the device specified by the first MNT$_DEVNAM item code in the item list; it mounts the volume specified by the second MNT$_VOLNAM code on the device specified by the second MNT$_DEVNAM code, and so on for all specified volumes and devices. Thus, there must be an equal number of these two item codes in the item list.

When a tape volume set is being mounted, the number of MNT$_DEVNAM item codes specified need not be equal to the number of MNT$_VOLNAM item codes specified, because more than one volume can be mounted on the same device.

#### MNT$_VOLSET

Specifies the name of a volume set. The buffer must contain a character string from 1 to 12 alphanumeric characters, which is the volume set name.

An ISO 9660 volume set name can be from 1 to 128 characters in length.

Volume set names must be unique in the first 12 characters. In addition, if the first 12 characters of the volume set name are the same as the first 12 characters of any volume label, a lock manager deadlock will occur. To avoid this problem, you must override either the volume label (by using the MNT$_VOLNAM item code) or the volume set name (by using the MNT$_VOLSET item code).

When you specify MNT$_VOLSET, volumes specified by the MNT$_VOLNAM item code are bound into a new volume set or added to an existing volume set, depending on whether the name specified by MNT$_VOLSET is a new or already existing name.

When you specify MNT$_VOLSET to add volumes to an existing volume set, the root volume (RVN1) must either (1) already be mounted or (2) be specified first (by the MNT$_DEVNAM and MNT$_VOLNAM item codes) in the item list.

When you specify MNT$_VOLSET to create a new volume set, the first volume specified (by the MNT$_DEVNAM and MNT$_VOLNAM item codes) in the item list becomes the root volume.

#### MNT$_VPROT

Specifies the protection to be assigned to the volume. The buffer must contain a longword protection mask, which specifies the four types of access allowed to the four categories of user.

The protection mask consists of four 4-bit fields. Each field grants or denies read, write, logical, and physical access to a category of users. Cleared bits grant access; set bits deny access. The following diagram depicts the structure of the protection mask:

If you do not specify MNT$_VPROT or specify it as the value 0, the volume receives the protection that it was assigned when it was initialized. To specify MNT$_VPROT for a Files-11 structured volume, the caller must either own the volume or have VOLPRO privilege.

#### MNT$_WINDOW

Specifies the number of mapping pointers to be allocated for file windows. The buffer must contain a longword value in the range 7 to 80. This value overrides the default value that was applied when the volume was initialized. The MNT$_WINDOW item code applies only to disks.

When a file is opened, the file system uses the mapping pointers to access the data in the file. To specify MNT$_WINDOW, you need OPER privilege.

### Description

> The Mount Volume service mounts a tape, disk volume, or volume set and specifies options for the mount operation.

> When a subprocess mounts a private volume without explicitly allocating the device, the master process of the job becomes the owner of this device. This provision is necessary because the subprocess can be deleted and the volume should remain privately mounted for this job.

> When a subprocess explicitly allocates a device and then mounts a private volume on this device, this subprocess retains the device ownership. In this case, only subprocesses of the device owner, and processes with SHARE privilege, have access to the device.

> The $MOUNT service uses the following system resources to mount volumes with group or systemwide access allowed:

> - Nonpaged pool
> - Paged pool

> When $MOUNT mounts a disk volume, the logical name DISK$volume-label is always created. If you specify a logical name in the mount request that is different from DISK$volume-label, there will be two logical names associated with the device.

> If the logical name of a volume is in a process-private table, then the name is not deleted when the volume is dismounted.

> Required Access or Privileges

> To mount a volume on a device, you must have read or control access to that device.

> To mount a particular volume, the caller must either own or have privilege to access the specified volume or volumes. The privileges required depend on the operation and are listed with the item codes that specify the operation.

> The calling process must have TMPMBX or PRMMBX privilege to perform an operator-assisted mount. SECURITY privilege is required to enable protected subsystems.

> Required Quota

> None

> Related Services

> $ALLOC, $ASSIGN, $BRKTHRU, $BRKTHRUW, $CANCEL, $CREMBX, $DALLOC, $DASSGN, $DELMBX, $DEVICE_SCAN, $DISMOU, $GETDVI, $GETDVIW, $GETMSG, $GETQUI, $GETQUIW, $INIT_VOL, $PUTMSG, $QIO, $QIOW, $SNDERR, $SNDJBC, $SNDJBCW, $SNDOPR

### Condition Values Returned

> SS$_NORMAL | The service completed successfully.
> SS$_ACCVIO | The item list or an address specified in the item list cannot be accessed.
> SS$_BADPARAM | A buffer length of 0 was specified with a nonzero item code; an illegal item code was specified; or no device was specified.
> SS$_NOGRPNAM | The caller does not have GRPNAM privilege.
> SS$_NOHOMEBLK | Files-11 home block not found on volume.
> SS$_NOOPER | The caller does not have the required OPER privilege.
> SS$_NOPRIV | The caller does not have sufficient privilege to access a specified volume.
> SS$_NOSUCHDEV | The specified device does not exist on the host system.
> SS$_NOSYSNAM | The caller does not have SYSNAM privilege.

The $MOUNT service can also return a condition value that is specific to the Mount utility. The symbolic definition macro $MOUNDEF defines these condition values.

## $MTACCESS

> Allows installations to provide their own routine to interpret and output the accessibility field in the VOL1 and HDR1 labels of an ANSI labeled magnetic tape.

### Format

> SYS$MTACCESS lblnam ,[uic] ,[std_version] ,[access_char] ,[access_spec] ,type

### C Prototype

> int sys$mtaccess ( unsigned int *lblnam, unsigned int uic, unsigned int std_version, unsigned int access_char, unsigned int access_spec, unsigned int type);

### Arguments

> #### lblnam

> OpenVMS usage: | address
> type: | longword (unsigned)
> access: | read only
> mechanism: | by reference

> ANSI label to be processed. The lblnam argument is the address of a longword containing the label. On input, the label passed is either the VOL1 or HDR1 label read from the magnetic tape; on output of labels, the value of this field is 0. The type of label passed is determined by type.

> #### uic

> OpenVMS usage: | uic
> type: | longword (unsigned)
> access: | read only
> mechanism: | by value

> UIC of the user performing the operation. The uic argument is a longword containing the UIC.

> #### std_version

> OpenVMS usage: | longword_unsigned
> type: | longword (unsigned)
> access: | read only
> mechanism: | by value

> Decimal equivalent of the ANSI standard version read from the VOL1 label. The std_version argument is a longword containing the standard version number.

> #### access_char

> OpenVMS usage: | longword_unsigned
> type: | longword (unsigned)
> access: | read only
> mechanism: | by value

> Accessibility character specified by the user. The access_char argument is a byte containing the accessibility character used for the output of labels.

> #### access_spec

> OpenVMS usage: | longword_unsigned
> type: | longword (unsigned)
> access: | read only
> mechanism: | by value

> Value specifying whether the accessibility character passed in access_char was specified by the user.

> The access_spec argument is a byte containing one of the following values:

> Value | Meaning
> --- | ---
> MTA$K_CHARVALID | Yes
> MTA$K_NOCHAR | No

> This argument is used only for the output of labels.

> #### type

> OpenVMS usage: | longword_unsigned
> type: | longword (unsigned)
> access: | read only
> mechanism: | by value

> Type of accessibility field to process.

> The type argument is a byte containing one of the following values:

> Value | Meaning
> --- | ---
> MTA$K_INVOL1 | Input a VOL1 label
> MTA$K_INHDR1 | Input a HDR1 label
> MTA$K_OUTVOL1 | Output a VOL1 label
> MTA$K_OUTHDR1 | Output a HDR1 label

### Description

> The Magnetic Tape Accessibility service allows installations to provide their own routine to interpret and output the accessibility field in the VOL1 and HDR1 labels of ANSI labeled magnetic tapes. The installation can override the default routine by providing an MTACCESS.EXE executive loaded image.

> The default installation routine first checks the ANSI standard version of the label. For magnetic tapes with a version number of 3 or less, the routine outputs either a blank or the character you specified. On input of these magnetic tapes, the routine checks for a blank and returns the value SS$_FILACCERR if the field is not blank.

> For magnetic tapes with a version number greater than 3, the routine outputs either the character specified by the access_char argument or an ASCII 1 if no character was specified. On input of these magnetic tapes, the routine checks for a blank. If the field is blank, R0 is set to 0. In that case, you are given full access and protection is not checked. If the field contains an ASCII 1, and the VOL1 Implementation Identifier field contains the system code, R0 is set to SS$_NORMAL. In that case, the protection is checked.

> If the field is not blank and does not contain an ASCII 1, R0 is set to SS$_FILACCERR, which forces you to override accessibility checking and allows the magnetic tape file system to check protection.

> The following table summarizes the results of label input check:

> Contents of R0 | Result
> --- | ---
> SS$_NORMAL | Check the protection on the magnetic tape.
> 0 | Give the user full access. Protection is not checked.
> SS$_FILACCERR | Check for explicit override, then check protection.

> Note that the default accessibility routine does not output SS$_NOVOLACC or SS$_NOFILACC. These statuses are included for the installation's use, and the magnetic tape file system handles these cases.

> The magnetic tape file system calls $MTACCESS to process the accessibility field in the VOL1 and HDR1 labels. After a call to the system service, the magnetic tape file system checks that the installation did not move the magnetic tape. If the magnetic tape was moved, the magnetic tape file system completes the current operation with an SS$_TAPEPOSLOST error. Finally, it processes the remainder of the label according to the status returned by $MTACCESS.

> Required Access or Privileges

> Because accessibility is an installation-provided routine, the operating system cannot determine which users have the authority to override the processing of this field. However, the magnetic tape file system allows only operator class users to deal with blank magnetic tapes so that a user must have both OPER and VOLPRO privileges to initialize or mount blank magnetic tapes.

> Required Quota

> None

> Related Services

> $ADD_HOLDER, $ADD_IDENT, $ASCTOID, $CHECK_ACCESS, $CHKPRO, $CREATE_RDB, $ERAPAT, $FIND_HELD, $FIND_HOLDER, $FINISH_RDB, $FORMAT_ACL, $FORMAT_AUDIT, $GET_SECURITY, $GRANTID, $HASH_PASSWORD, $IDTOASC, $MOD_HOLDER, $MOD_IDENT, $PARSE_ACL, $REM_HOLDER, $REM_IDENT, $REVOKID, $SET_SECURITY

### Condition Values Returned

> SS$_NORMAL | The service completed successfully.
> SS$_FILACCERR | The accessibility characteristic in the HDR1 label is not blank and you cannot access the file without overriding the field.
> SS$_NOFILACC | The user has no access to the file.
> SS$_NOVOLACC | The user has no access to the volume.

## $NUMTIM

> Converts an absolute or delta time from 64-bit system time format to binary integer date and time values.

> On Alpha systems, this service accepts 64-bit addresses.

### Format

> SYS$NUMTIM timbuf ,[timadr]

### C Prototype

> int sys$numtim (unsigned short int timbuf [7], struct _generic_64 *timadr);

### Arguments

> #### timbuf

> OpenVMS usage: | vector_word_unsigned
> type: | word (unsigned)
> access: | write only
> mechanism: | by 32- or 64-bit reference (Alpha)
> mechanism: | by 32-bit reference (VAX)

> Buffer into which $NUMTIM writes the converted date and time. The timbuf argument is the 32-bit address (on VAX systems) or the 32- or 64-bit address (on Alpha systems) of a 7-word structure.

> The following diagram depicts the fields in this structure:

If the timadr argument specifies a delta time, $NUMTIM returns the value 0 in the year since 0 and month of year fields. It returns in the day of month field the number of days specified by the delta time.

#### timadr

OpenVMS usage: | date_time
type: | quadword
access: | read only
mechanism: | by 32- or 64-bit reference (Alpha)
mechanism: | by 32-bit reference (VAX)

The 64-bit time value to be converted. The timadr argument is the 32-bit address (on VAX systems) or the 32- or 64-bit address (on Alpha systems) of a quadword containing this time. A positive-time value represents an absolute time, while a negative time value indicates a delta time.

If you do not specify timadr, $NUMTIM returns the current system time.

If timadr specifies the value 0, $NUMTIM returns the base date (November 17, 1858).

### Condition Values Returned

> SS$_NORMAL | The service completed successfully.
> SS$_ACCVIO | The 64-bit time value cannot be read by the caller, or the buffer cannot be written by the caller.
> SS$_IVTIME | The specified delta time is equal to or greater than 10,000 days.

Previous | Next | Contents | Index

| privacy and legal statement |
4527PRO_071.HTML