Managing a Large Environment Using Global Data Manager (GDM)

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Offhost Backups

As the challenges of backup continue to grow, everyone is looking for new ways to meet these challenges. One of the new backup methods is sometimes referred to as serverless or server-free backup. The more correct name is offhost backup. This backup method uses a separate backup agent located on either a media server or a third-party copy (3PC) device to actually move the data from the client disk to storage.

Figure 7.3 shows an example of an implementation of offhost backup using NetBackup. The backup agent in this case could be either a media server or a third-party copy (3PC) device that implements SCSI Extended Copy commands. Many types of 3PC devices can act as backup agents, such as

• Bridge

• Router

• Robotic library

• Disk array

One of the key elements for offhost backups is that the backup must be done from a frozen image. Any of the frozen image types listed in the section can be used. Sometimes this feature is confused with the LAN-free backup feature such as the NetBackup SSO feature. If the requirement is to keep the backup data off the LAN or to do a frozen image backup so that the application can continue to be available, either SSO or frozen image backups will fulfill the need. If the problem is that the backup overhead is too much for the application server to handle, offhost backup is the solution. By using offhost backup, you are moving the disk reads and the tape writes to a separate backup agent who will actually perform this work.

Figure 7.3: Offhost backup.

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