How the NetBackup Accelerator works on UNIX/Linux
|Article:HOWTO67421|||||Created: 2012-02-06|||||Updated: 2013-12-06|||||Article URL http://www.symantec.com/docs/HOWTO67421|
At the next backup, NetBackup identifies data that has changed since the previous backup. It compares the client's file system to the track log from the previous backup, or it uses the Windows change journal, if enabled. (The change journal applies to NTFS file systems only.)
The NetBackup client sends to the media server a tar backup stream that consists of the following: The client's changed blocks, and the previous backup ID and data extents (block offset and size) of the unchanged blocks.
The media server reads the client's changed blocks and the backup ID and file system descriptors of the unchanged blocks. From the backup ID and file system descriptors, the media server locates the rest of the client's data in existing backups.
Figure: NetBackup client: Accelerator backup stream shows how an Accelerator backup stream is composed.
Figure: NetBackup media server constructs backup image shows how the media server constructs a backup image from the Accelerator stream and from previous backups:
Figure: Process overview of Accelerator backup recaps Accelerator details in the context of the principal NetBackup processes.
Article URL http://www.symantec.com/docs/HOWTO67421