Technical data

Using BACKUP
11.3 Formulating a Backup Strategy
file entries. (The primary file, which uses the same file header but
allocates different data storage blocks, is also restored.)
However, despite the error message, note that there is no BACKUP
error or loss of data.
You do not have to change tapes or disks during a backup if any of the following
statements is true:
• All of the files fit on a single piece of storage media.
• Your site uses a tape loader.
• You have several disk or tape drives available.
In these cases, the backup can be performed by a batch job that runs late at
night or at some other time when interactive use of the system is likely to be at a
minimum. Section 11.15.7 contains some sample command procedures that you
can run in a batch job to back up your disks.
11.4 Understanding the Backup Interfaces
Two interfaces are available to the OpenVMS Backup utility:
• The BACKUP command, which is a command in the DCL command line
interface
• The Backup Manager, which is an interactive screen-oriented interface
11.4.1 The BACKUP Command Line
To back up files, you must specify what you want to back up (the input) and
where you want BACKUP to place the resultant save set or file (the output). You
can also use BACKUP qualifiers to perform different functions depending upon
their position on the command line:
BACKUP/qualifiers input-specifier/qualifiers output-specifier/qualifiers
Table 11–2 lists the types of BACKUP command qualifiers.
Table 11–2 BACKUP Command Qualifier Types
Type Position Effect
Command
qualifier
Anywhere on the
command line
Affects both input and output specifiers.
Input specifier
qualifier
Directly after the input
specifier
Affects only the input specifier.
Output specifier
qualifier
Directly after the output
specifier
Affects only the output specifiers.
When you use BACKUP, make sure you place BACKUP qualifiers in their
correct positions on the command line. For more information about the BACKUP
command line, refer to the OpenVMS System Management Utilities Reference
Manual.
Using BACKUP 11–5