Backup

 

Selecting a Backup Type: Full or Incremental

How to Read Table

The rows in Table 5-1 are independent of each other and show

5-1

different situations.

The age of the backups increases from right to left, so that the far left is the oldest and the far right is the most recent backup.

The full and IncrX represent still-protected objects of the same owner. Any existing IncrX that is not protected can be used for restore, but is not considered for referencing on subsequent backup runs.

Examples:

In the second row, there is a full, still protected backup and an Incr2

 

 

is running. There is no Incr1, so the backup is executed as an Incr1.

 

In the fifth row, there is a full backup, an Incr1 and another

 

 

incremental is running. Data Protector references the currently

 

 

running backup to the previous incremental, that is Incr1.

 

In the eighth row, the Incr3 is executed as Incr2, and in the eleventh

 

 

row, the Incr3 is executed as Incr1.

How to Select the

If you perform an interactive backup, you are prompted to select the

Backup Type

backup type. When scheduling a backup, you specify the backup type in

 

the Schedule Backup dialog. You can, for example, create a schedule

 

that runs the same backup specification as full on Saturday and as Incr1

 

on all working days.

Backup Type and

Keep in mind that full backups enable a simple and efficient restore, but

the Restore

require many media that can hold multiple versions of the entire backed

Process

up data. The time required to complete a backup is rather long.

 

Incremental backups require fewer media resources, but have a more

 

complex restore algorithm. Compare the following two examples:

 

1.

full ; Incr ; Incr ; Incr ; Incr (-> time)

 

 

This example requires a shorter backup time and the media space

 

 

required is lower. The restore process is more complex; many media

 

 

need to be accessed, and the required time is longer if you want to

 

 

restore to the state of the last Incr.

 

2.

full ; Incr1 ; Incr1 ; Incr1 ; Incr1 (-> time)

 

 

This example requires more time for backup and the media space

 

 

consumption is a bit higher if compared to the first example. The

 

 

restore process is simple; few media are needed, and the time spent

 

 

on performing a restore is shorter than in the first example.

Chapter 5

215

Page 245
Image 245
HP B6960-90078 manual How to Read Table, Examples, How to Select, Backup Type, Process