NetBackup Overview - Backup Types

Description

NetBackup 7.6.x features a number of backup types that are included standard, out-of-the-box. Understanding the fundamental behaviors of each backup type will aid in the deployment and ongoing management of a successful backup environment.

Selecting a Type of Backup:

When a policy is created or modified, the "Type of Backup" Attributes panel can be accessed by selecting the Schedules tab.  
The Attributes list displays only the backup attributes available to the current policy.

*** If the schedule is a relocation schedule created as part of a basic disk staging storage unit, no backup type selection is needed. 

Understanding Standard Backup Types:

There are (5) standard backup types available with NetBackup 7.6.x The following table provides a summary of each standard backup type. 
 

Standard Backup Type Caveats:

for Cumulative Incremental Backup: 
By default, if the time between file creation and a full or a differential incremental backup is less than 5 minutes, the differential or cumulative incremental backup may yield unexpected results. The backups are successful, but additional files are backed up. This is often due to the client waiting for acknowledgement from the server of the completed backup. The minimum time allowable for this action is 300 seconds. Additionally the archive bit will not be cleared if no response is received from the server which will result in NetBackup backing up all the same data as the previous last backup.

for User Backup: 
User Backups can be run only during periods that are defined in the Schedule Start Window tab.

User Backups that attempt to run during a closed window will result in the job failing.  

Additional Backup Types:

A total of (8) additional backup types are available with NetBackup 7.6.x through separate license and/or installation of separate agents.

The following table provides summary of these additional (8) backup types.
 

Additional Backup Types Caveats:

for Application Backups: Complete information can be obtained from the related NetBackup Guide for the respective Database. 

for Vault Catalog Backup: Configuration of one of two schedule attribute combinations is required to be selected or the schedule can not be saved. These are,

• Check and configure Multiple Copies
• Check Override policy storage selection, Override policy volume pool and specify retention.

  *** The selected storage unit selection should not be "Any Available". 

About Incremental Backups:

In order to utilize an Incremental Backup, a Full Backup must be run and completed successfully. If no full backup is run, the incremental automatically performs the role of a full backup. To determine the retention of differential and cumulative incremental backups to prevent a gap in backup coverage. The following table provides summary of retention requirements for incremental backups.

You can use a combination of cumulative and differential incremental backups together to get the advantages of both methods.
For example, assume a set of schedules with the following backup frequencies and retention periods.
(Notice that the differential incremental backups occur more often.)
 

The schedules described above will effectively result in the following series of backups.

Note: The job from the automatic schedule with a lower frequency (longer period between backups) always takes precedence.
Thus, the above example produces the following results:

• Every other day a differential incremental backup occurs, which usually has a minimum backup time.
• On alternate days, a cumulative incremental backup occurs, which requires more time than the differential backup, but not as much time as a full backup.
  The differential backup can now be expired.
• To recover all files may require (at most), two incremental backups in addition to the most recent full backup. The combination of backups usually means less restore time than if all differential incremental backups were used. The full backups can be done less often if the amount of data being backed up by the incremental backup is small. 

References:

NetBackup 7.6 Administration Guide

Terms of use for this information are found in Legal Notices.