Technical data

Managing Storage Media
9.4 Protecting Volumes
9.4.2 Protecting Tape Volumes
The system protects magnetic tapes only at the volume level. You establish
protection when you initialize tape volumes; after that, the Mount utility
(MOUNT) enforces the protection that you have established.
You can use two levels of protection for tape volumes:
Level of Protection Description
Guidelines of the ISO
standard
The ISO standard, which is the first level of protection, is
encoded in the accessibility field of the first volume label
written on the magnetic tape. With this protection scheme, you
can protect tape volumes in environments where interchange
exists between the OpenVMS system and the operating system
that is not OpenVMS.
UIC-based protection
scheme supported by
system software
This second level of protection is encoded in the second volume
label written on the magnetic tape. Only OpenVMS systems
check this scheme; it is ignored in any interchange with
operating systems that are not OpenVMS.
Standard-Labeled Tape Protection
The OpenVMS tape file system bases its accessibility protection on the ISO
standards. This protection allows an installation routine to use a routine that
interprets the contents of the volume- and header-label accessibility field. Refer
to the $MTACCESS system service in the OpenVMS System Services Reference
Manual for more information about installation routines.
Access Types with Default Protection
When you do not supply a protection code during initialization, all users receive
read and write access, explained in Table 9–12.
Table 9–12 Access Types for Tape Volume Protection
Access Type Gives you the right to...
Read Examine, print, or copy files from the volume.
Write Append or write files to the volume.
The security profile of a tape volume is stored in the ANSI VOL1 and VOL2
labels written on the tape. The VOL2 label contains system-specific information.
To override the creation of VOL2 labels, specify the /INTERCHANGE qualifier
with the INITIALIZE command or the INIT$_INTERCHANGE itemcode on the
$INIT_VOL system service.
Foreign Volume Protection
The operating system also supports foreign tape volumes. (Foreign volumes
either lack the standard volume label or have been mounted with the /FOREIGN
qualifier.) When a tape volume is mounted with the /FOREIGN qualifier, users in
the system and owner categories are always given full access (read, write, logical,
and physical), regardless of what is specified in the protection code.
9–26 Managing Storage Media