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Ordinarily, when you mount volumes, the system imposes a format on each volume that allows you to read, write, create (or execute), and delete files. These mounted volumes have the format of the OpenVMS operating system.
If you specify the /FOREIGN qualifier when you mount a volume, the system does not impose a format on the media, and you cannot access the files on the mounted volume. Use the /FOREIGN qualifier to mount volumes with formats of operating system that are not OpenVMS or with private formats.
Because foreign volumes are not file-structured, you must access them as follows:
At times, the Backup utility (BACKUP) requires you to mount volumes with the /FOREIGN qualifier, when you restore an entire disk, for example. For details, see the OpenVMS System Management Utilities Reference Manual.
How to Perform This Task
When mounting volumes, follow these steps:
MOUNT device-name volume-label logical-name
| device-name | Specifies the physical device name or logical name of the device on which the volume is to be mounted. |
| volume-label | Specifies the label on the volume. |
| logical-name | Defines a logical name to be associated with the device. |
Once invoked, the Mount utility does the following:
Using Qualifiers with the MOUNT Command
Under special conditions, you must add qualifiers to the MOUNT command; for example:
MOUNT/SYSTEM device-name volume-label logical-name
MOUNT/SYSTEM/CLUSTER device-name volume-label logical-name
Table 8-12 and Table 8-13 show, respectively, the qualifiers you can use when you mount disks and tapes.
The following sections explain how to perform these tasks:
| Task | Section |
|---|---|
| Use MOUNT command qualifiers when you mount disks | Section 8.5.1 |
| Use MOUNT command qualifiers when you mount tapes | Section 8.5.2 |
| Assist users with mounting | Section 8.5.3 |
| Mount a volume with a protected subsystem | Section 8.5.4 |
| Modify disk volume characteristics | Section 8.5.5 |
Table 8-12 lists MOUNT command qualifiers you can use to mount disks. The OpenVMS System Management Utilities Reference Manual has more information about each qualifier.
| Qualifier | Description |
|---|---|
| /ACCESSED= n |
Requires OPER privilege; specifies the approximate number of
directories that will be in use concurrently on the volume. (This
qualifier is obsolete for ODS-2.) For example, on a large 500 megabyte
(MB) disk you might select a value of 40, but on a small disk you might
specify the following:
$ MOUNT/ACCESSED=2 DUA3:
|
| /ASSIST |
Directs the mount operation to allow operator or user intervention if
the mount request fails. The /ASSIST qualifier is the default except
during system startup. Encourage users to take advantage of this
feature, which repeatedly alerts the operator of a mount request until
the request is satisfied.
To disable operator-assisted mounts, enter a command like the following: $ MOUNT/SYSTEM/NOASSIST DUA1: SALES_95
|
| /BIND= volume-set-name |
Creates a volume set of one or more disk volumes or adds
one or more volumes to an existing volume set. For example:
$ MOUNT/SYSTEM/BIND=CLIENTS DUA0:,DUA1: EUROPE,ASIA
See Section 8.6.1.2 for details. |
| /CACHE= keyword |
Controls whether caching limits established at system generation are
disabled or overridden. For example:
$ MOUNT/CACHE=(EXTENT=60,FILE_ID=60,QUOTA=20) -
This command mounts a device labeled FILES and assigns the logical name WORK. The /CACHE qualifier enables an extent cache of 60 entries, a file identification cache of 60 entries, and a quota cache of 20 entries. |
| /CLUSTER |
Requires SYSNAM privilege; specifies that after a volume is
successfully mounted on the local node, or if it is already mounted
with the /SYSTEM qualifier on the local node, it is to be mounted on
every other node in the existing OpenVMS Cluster environment (that is,
the volume is to be mounted clusterwide). For example:
$ MOUNT/SYSTEM/CLUSTER DUA1: SALES_95
|
| /COMMENT= "string" |
Specifies additional information to be included with the operator
request when the mount operation requires operator assistance. For
example:
$ MOUNT/SYSTEM DYA1: SALES_95/COMMENT="Vol. in Rack 2."
|
| /EXTENSION= n |
Requires OPER privilege; specifies the number of blocks by which disk
files are to be extended on the volume unless otherwise specified by an
individual command or program request.
The cluster size sets the initial disk block allocation; the /EXTENSION
qualifier determines how the file grows. For example, for a small disk
with a cluster size of 1 disk block, you might select an extension size
of 2 disk blocks:
$ MOUNT/EXTENSION=2 DUA3:
|
| /FOREIGN |
Indicates that the volume is not in the standard format used by the
operating system. Use this qualifier if you want to mount a disk volume
with a file structure other than Files--11 or ISO 9660; for example
(using DISK as a logical name):
$ MOUNT/FOREIGN DISK
|
| /MEDIA_FORMAT=CDROM | Mounts a volume assuming the media to be ISO 9660 (or High Sierra) formatted. |
| /[NO]MOUNT_VERIFICATION |
Enables or disables the mount verification feature on disks. By
default, the mount verification feature is enabled. If a device goes
off line or becomes write-locked, mount verification notifies the
operator of the error condition, and then checks to see that the volume
identification before and after the error condition are identical.
To disable mount verification, enter a command like the following: $ MOUNT/SYSTEM/NOMOUNT_VERIFICATION DUA1: ACCOUNTS_DUE
|
| /OVERRIDE= keyword | Inhibits one or more protection checks that the MOUNT command performs. |
| /PROTECTION= keyword |
Specifies the protection code to be assigned to the volume. Keywords
are the following:
See Section 8.4.1 for details. |
| /SHARE |
Specifies that other users can access the volume.
(However, you must use the /SYSTEM qualifier to mount public volumes.)
Two users can access a private volume simultaneously if they both use
MOUNT/SHARE. For example:
$ MOUNT/SHARE DLA0: COST_ACCOUNT
Using the MOUNT/SHARE command on disks already mounted with the /SYSTEM qualifier retains a lock on disk availability even if the disk is dismounted on a systemwide basis. This practice is not usually used for the system disk, but it can occur as a result of invoking a general-purpose command procedure that is sometimes used on system and nonsystem disks. If the DISMOUNT.EXE program is opened by a user and another user enters the MOUNT/SHARE command on the system disk, a subsequent dismount may produce a warning message that the disk cannot be dismounted. To prevent the message, install the DISMOUNT.EXE image. |
| /SUBSYSTEM |
Enables the processing of subsystem
ACEs. (The command MOUNT/SUBSYSTEM requires the SECURITY privilege.) By
default, the disk from which you boot has /SUBSYSTEM enabled but other
disks do not. The following command uses the MOUNT command with the
/SUBSYSTEM qualifier to enable the processing of subsystem ACEs on the
DUA0: device (DOC is the volume label; WORK8 is an optional logical
name for the volume):
$ MOUNT/SUBSYSTEM/SYSTEM DUA0: DOC WORK8
|
| /SYSTEM |
Requires SYSNAM privilege; makes the volume public, that is, available
to all users of the system, as long as the UIC-based volume protection
allows them access.
The following command mounts the volume labeled WORK and makes it
available systemwide:
$ MOUNT/SYSTEM DUA1: WORK
|
| /UCS_SEQUENCE= escape_sequence | Supplies the escape sequence to select the coded graphic character set, a requirement when mounting an ISO 9660 volume for one of its Supplementary Volume Descriptors (SVDs). |
| /UNDEFINED_FAT | Establishes default file attributes to be used for records on ISO 9660 media for which no record format has been specified. |
| /WINDOWS= n |
Requires OPER privilege; specifies the number of mapping pointers to be
allocated for file windows.
The default number of windows is set with the INITIALIZE command. The
following example specifies a modest number of pointers:
$ MOUNT/WINDOWS=4 DUA3:
|
Table 8-13 lists MOUNT command qualifiers you can use to mount a tape volume. For a complete list of MOUNT command qualifiers, see the OpenVMS System Management Utilities Reference Manual.
Unless otherwise noted, you must have VOLPRO privilege to use any of these qualifiers when the volume is a standard-labeled volume containing protection that disallows your process from accessing the volume.
| Qualifier | Description |
|---|---|
| /BLOCKSIZE= n | Specifies the block size for the magnetic tape. The range of valid values for n varies, depending on the density of the volume, whether the data is for input or output, and whether the operation uses OpenVMS RMS. By default, the system writes 2048-byte blocks. |
| /CACHE=TAPE_DATA |
Requires OPER privilege; enables the write cache for a tape device if
the tape controller supports one. /NOCACHE is the default for mounting
tape devices.
You must specify TAPE_DATA to enable write caching. The write buffer stays enabled even after you dismount the tape. |
| /FOREIGN | Indicates that the volume is not in the standard format used by the operating system. |
| /HDR3 | Controls whether special header labels are written on a tape volume. This is the default. |
| /[NO]MOUNT_VERIFICATION |
Enables or disables the mount verification feature on magnetic tapes.
By default, the mount verification feature is enabled. If a device goes
off line or becomes write-locked, mount verification notifies the
operator of the error condition, and then checks to see that the volume
identification before and after the error condition are identical.
To disable mount verification, enter a command like the following: $ MOUNT/SYSTEM/NOMOUNT_VERIFICATION MUA1: ACCOUNTS_DUE
|
| /OVERRIDE= keyword |
Inhibits one or more of the access checks that the MOUNT command
performs. For example:
$ MOUNT/OVERRIDE=IDENTIFICATION MFA0:
This command overrides the volume identification field, thus mounting a magnetic tape on MFA0: without a label specification. |
| /OWNER_UIC= uic | Requests that the specified UIC be assigned ownership of the volume while it is mounted, overriding the ownership recorded on the volume. Or, if you are mounting a volume using the /FOREIGN qualifier, requests an owner UIC other than your current UIC. |
| /PROCESSOR= keyword |
For magnetic tapes and Files--11 Structure Level 1 disks, requests that
the MOUNT command associate an ancillary control process (ACP) to
process the volume.
You must have the operator user privilege OPER to use the /PROCESSOR qualifier. Keywords are the following:
The /PROCESSOR qualifier causes MOUNT to override the default manner in which ACPs are associated with devices. For example: $ MOUNT/PROCESSOR=SAME:MTA1: MFA0:
This command directs MOUNT to mount a magnetic tape on MFA0: using the same ACP process currently associated with the MTA1: device. |
| /PROTECTION= code | Specifies the protection code to be assigned to the volume for the duration of the mount. See Section 8.4.2 for details. |
| /RECORDSIZE= n | Specifies the number of characters in each record of a magnetic tape volume. Use this qualifier when you mount a volume that has a file without a second header label (such as RT--11 volumes), or when you mount volumes with the /FOREIGN qualifier, to provide RMS with the size of fixed-length records or the maximum size of variable-length records. |
Two other qualifiers that are important for mounting tape volumes are /INITIALIZE and /AUTOMATIC, which are explained in Section 8.8.2.2 and Section 8.8.2.3, respectively.
Example
$ MOUNT MU: TEST_FILES %MOUNT-I-OPRQST, Please mount volume TEST_FILES in device _MUA2: %MOUNT-I-MOUNTED, TEST_FILES mounted on _MUA2:
In this example, the MOUNT command requests an available RA90 device for the volume labeled TEST_FILES. After you physically mount the volume in the device named in the response from MOUNT, the system completes the operation. Note that the device is automatically allocated by MOUNT.
Upon successful completion of the operation, MOUNT notifies you with a message sent to SYS$OUTPUT. If the operation fails for any reason, MOUNT notifies you with an error message.
Large sites often have operators assigned to assist users with mounting volumes. Section 2.4.6 explains how users can send requests to operators. Section 2.4.7 briefly explains how operators reply to those requests.
When a user requests you to mount a specific disk or tape on a device, the following type of message appears on the operator terminal:
%%%%%%%%%%% OPCOM, <dd-mmm-yyyy hh:mm:ss:cc> %%%%%%%%%%% request <request-id>, from user <user-name>
The following steps indicate the sequence of events:
$ MOUNT DUA2: TEST_FILES/COMMENT="Shelf slot 6B"
%%%%%%%%%%% OPCOM, 28-MAY-1996 15:47:50.26 %%%%%%%%%%% request 5, from user MALCOLM Please mount volume TEST_FILES in device _DUA2: Shelf slot 6B
%MOUNT-I-OPRQST, Please mount volume TEST_FILES in device _DUA2: Shelf slot 6B
%MOUNT-I-MOUNTED,TEST_FILES mounted on _DUA2: %MOUNT-I-RQSTDON, operator request canceled -- mount completed successfully.
Instead of requesting a specific hardware device, such as DUA2:, for mounting a volume, users can make a generic MOUNT request. A generic MOUNT request specifies a type of device and lets you find an available device in that class. For example, to mount the volume CITIES on any tape drive whose name begins with MU, the user enters the following command:
$ MOUNT MU: CITIES/COMMENT="Slot 12c"
If the user has already allocated a drive whose name begins with MU, the Mount utility requests that you mount CITIES on that particular drive. If no device has been allocated, the Mount utility allocates the first available MU tape drive it finds and requests you to mount CITIES on that drive.
Sending Messages Back to Users
After you mount a disk or tape, follow these steps:
| REPLY Command Qualifiers | Description |
|---|---|
| /ABORT= identification-number "message-text" | Indicates that the user request is canceled. (The user's MOUNT command exits with an error status.) |
| /PENDING= identification-number "message-text" | Indicates that the request has been put in a wait state until it can be completed. This command implies that the originating request was either a REQUEST/REPLY or a MOUNT command. The user cannot enter other commands until the operator fulfills or aborts the request. |
| /TO= identification-number "message-text" | Indicates that the request is fulfilled. (Processing continues.) |
REPLY/TO=identification-number SUBSTITUTE device-name
Examples
$ REPLY/TO=24 "SUBSTITUTE DUA1:"
$ MOUNT/ASSIST MKB500: MYDATA %MOUNT-I-OPRQST, Please mount volume MYDATA in device _MKB500: %MOUNT-I-OPREPLY, Substitute MKA100: 11:44:28.71, request 1 was completed by operator _FTA8:
See the OpenVMS DCL Dictionary for a complete list of REPLY qualifiers and their functions. See Section 8.8.2.4 for instructions for entering REPLY commands after you mount a volume set with automatic switching disabled.
Security is usually based on control rights that are granted or denied to the user. In a protected subsystem, however, security is based on access controls assigned to the subsystem. The subsystem acts as a gatekeeper that grants or denies users access to objects belonging to the subsystem.
Unprivileged users can build and manage protected subsystems. You must be involved at two points in the process:
Caution
Anyone who mounts a subsystem is responsible for knowing what is on the volume being mounted. Digital strongly recommends that you find out what is on a volume before you mount a subsystem. Without this knowledge, you might inadvertently subvert system security and jeopardize the privacy of users' data.For example, a user with malicious intent who has privileges on one OpenVMS Cluster node might place an application with a subsystem identifier on a volume and then request an unsuspecting operator or system manager to mount the volume on another node. Because the application has a subsystem identifier, the application appears to belong to a subsystem for which it is unauthorized.
How to Enable Protected Subsystems on a Trusted Volume
The system enables protected subsystems by default only on the system disk. For other disks, you must enable subsystems every time you mount a volume. A person with the SECURITY privilege can enable subsystems on a volume by using the /SUBSYSTEM qualifier on the MOUNT command.
You can dynamically turn on and off the processing of Subsystem ACEs with the DCL command SET VOLUME/SUBSYSTEM. This command is especially useful for the system disk, which is not mounted using the MOUNT command.
Example
The command in the following example mounts the volume labeled DOC on the DUA0: device. Subsystems on the volume are accessible. The MOUNT command also assigns the logical name WORK8.
$ MOUNT/SUBSYSTEM/SYSTEM DUA0: DOC WORK8
Use the DCL command SET VOLUME to modify the characteristics of one or more mounted Files--11 disk volumes. To use this command, you must have write access to the index file on the volume. If you are not the owner of the volume, you must have either a system UIC or the user privilege SYSPRV. You must then specify the name of one or more mounted Files--11 volumes.
The following examples illustrate how you can use the SET VOLUME command.
Examples
$ SET VOLUME/DATA_CHECK=(READ,WRITE) DKA100:
$ SET VOLUME/LABEL=LICENSES DKA100:
The DISKMOUNT.C program can help to speed up disk mounts at system startup time. The program reduces the MOUNT image activation time by directly calling the $MOUNT system service.
Note
DISKMOUNT.C does not support mounting of disks connected to an InfoServer, disks served using DFS, or stripe sets.
6017P022.HTM OSSG Documentation 22-NOV-1996 14:21:48.44
Copyright © Digital Equipment Corporation 1996. All Rights Reserved.