Technical data

Using Files and Directories
10.1 Understanding Extended File Specifications Features
In addition, the directory depth on a VAX is limited to 8 (or 16, using rooted
logicals).
Physical Backups of ODS-5 Volumes on VAX Systems
On OpenVMS VAX systems, BACKUP supports ODS-5 volumes only when you
specify the /PHYSICAL qualifier to back up a volume. The BACKUP /PHYSICAL
command causes BACKUP to make a block-by-block physical backup of the disk,
ignoring the structured contents of the disk.
On Alpha systems, you can use either the BACKUP /IMAGE or BACKUP
/PHYSICAL command.
10.2 Controlling Access to ODS-5 Volumes
System managers might choose to enforce one or both of the following restrictions:
• Prevent users on a VAX from accessing files on an ODS-5 volume.
• Prevent untested applications from accessing files on an ODS-5 disk. (You
can allow certain users to override this access control on an ODS-5 volume.)
The system manager can impose either of these restrictions by using normal
OpenVMS discretionary controls. Refer to the OpenVMS Guide to System
Security for more information.
The following sections contain examples of restrictions you can impose.
10.2.1 Preventing VAX Users from Accessing an ODS-5 Volume
Follow these steps to prevent a user from accessing an ODS-5 volume from a VAX
node:
1. Define an identifier (for example, VAX_NODE) to identify users running on
an OpenVMS VAX nod, for example:
$ RUN SYS$SYSTEM:AUTHORIZE
UAF> ADD /IDENTIFIER VAX_NODE
%UAF-I-RDBADDMSG, identifier VAX_NODE value %X80010037 added to rights database
2. On each VAX node, add VAX_NODE to the system rights list; for example:
$ SET RIGHTS_LIST /ENABLE /SYSTEM VAX_NODE
The /ENABLE qualifier in the command adds VAX_NODE to the system
rights list.
Also add this command to the SYSTARTUP_VMS.COM command procedure.
3. To prevent anyone on a VAX node from gaining access to an ODS-5 volume,
place an Access Control Entry (ACE) on the volume that denies access to
holders of the VAX_NODE identifier, for example:
$ SET SECURITY /CLASS=VOLUME ODS5_DISK /ACL=(ID=VAX_NODE,ACCESS=NONE)
Using Files and Directories 10–9