Understanding Types of Backups

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HP OpenVMS System Manager's Manual, Volume 1:...

Using BACKUP

Overview of BACKUP Tasks

Formulating a Backup Strategy

Understanding Types of Backups

The following table lists the types of backup operations.

Operation Description

File operation
Processes individual files or directories. Backing Up Files and Directories describes file operations.

Selective operation
Processes files or volumes selectively, according to criteria such as version number, file type, UIC, date and time of creation, expiration date, or modification date.

Performs selective save operations by using wildcard characters and input file-selection qualifiers (for example, /BACKUP, /BEFORE, /BY_OWNER [/OWNER_UIC], /CREATED, /EXCLUDE, /EXPIRED, /MODIFIED, and /SINCE). Backing Up Files and Directories describes selective operations.

Physical operation
Copies, saves, restores, or compares an entire volume in terms of logical blocks, ignoring any file structure.

Image operation
Processes all files on the input disk. The types of image operations are:
An image backup (also called a full backup) saves a copy of all the files on a disk (or volume) to a special file called a save set.

An image restore initializes the output disk and restores an entire volume.

An image copy operation initializes the output disk and copies an entire volume; the image backup is a logical duplicate of the contents of the disk.

An image compare operation compares the contents of entire volumes.

Because an image copy or backup operation processes all files on the input volume, you cannot specify file-selection qualifiers for these operations. You can, however, restore files and directories selectively from an image save set.

Incremental operation
The two types of incremental operations are:
An incremental backup saves only those files that have been created or modified since the most recent backup that was performed using the /RECORD qualifier. (The /RECORD qualifier records the date and time that the files are backed up.)

An incremental restore operation restores an incremental save set. Specify the command qualifier /INCREMENTAL to perform this operation. Restoring Incremental Backups describes incremental restore operations.

Operation	Description
File operation	Processes individual files or directories. Backing Up Files and Directories describes file operations.
Selective operation	Processes files or volumes selectively, according to criteria such as version number, file type, UIC, date and time of creation, expiration date, or modification date. Performs selective save operations by using wildcard characters and input file-selection qualifiers (for example, /BACKUP, /BEFORE, /BY_OWNER [/OWNER_UIC], /CREATED, /EXCLUDE, /EXPIRED, /MODIFIED, and /SINCE). Backing Up Files and Directories describes selective operations.
Physical operation	Copies, saves, restores, or compares an entire volume in terms of logical blocks, ignoring any file structure.
Image operation	Processes all files on the input disk. The types of image operations are: An image backup (also called a full backup) saves a copy of all the files on a disk (or volume) to a special file called a save set. An image restore initializes the output disk and restores an entire volume. An image copy operation initializes the output disk and copies an entire volume; the image backup is a logical duplicate of the contents of the disk. An image compare operation compares the contents of entire volumes. Because an image copy or backup operation processes all files on the input volume, you cannot specify file-selection qualifiers for these operations. You can, however, restore files and directories selectively from an image save set.
Incremental operation	The two types of incremental operations are: An incremental backup saves only those files that have been created or modified since the most recent backup that was performed using the /RECORD qualifier. (The /RECORD qualifier records the date and time that the files are backed up.) An incremental restore operation restores an incremental save set. Specify the command qualifier /INCREMENTAL to perform this operation. Restoring Incremental Backups describes incremental restore operations.

Two types of BACKUP operations, file and image, support converting ODS-5 file names to ODS-2 file names. Refer to Converting from ODS-5 Files to ODS-2 for more information.

Overview of BACKUP Tasks

Formulating a Backup Strategy