Symantec 7 manual About deduplication nodes, Host Description

22Planning your deployment

About the NetBackup Media Server Deduplication Option

Table 2-2	NetBackup deduplication servers
Host	Description

Deduplication storage	One host functions as the storage server for a deduplication node;
server	that host must be a NetBackup media server. The storage server
	does the following:
	■ Writes the data to and reads data from the disk storage.
	■ Manages that storage.
	The storage server also deduplicates data. Therefore, one host
	both deduplicates the data and manages the storage.
	Only one storage server exists for each NetBackup deduplication
	node.
	You can use NetBackup deduplication with one media server host
	only: the media server that is configured as the deduplication
	storage server.
Load balancing server	You can configure other NetBackup media servers to help
	deduplicate data. They perform file fingerprint calculations for
	deduplication, and they send the unique results to the storage
	server. These helper media servers are called load balancing
	servers.
	See “About deduplication fingerprinting” on page 117.
	You configure load balancing servers when you configure the
	deduplication storage server. Also, you can add a deduplication
	server later to a deduplication node.
	Load balancing servers also perform restore and duplication jobs.
	Symantec recommends that you add load balancing servers only
	after the storage server reaches maximum CPU utilization. For
	more information about how to use load balancing servers, see
	the following Symantec tech note:
	http://entsupport.symantec.com/docs/338123

About deduplication nodes

A media server deduplication node is a deduplication storage server, load balancing servers (if any), the clients that are backed up, and the storage. Each node manages its own storage. Deduplication within each node is supported; deduplication between nodes is not supported.

Multiple media server deduplication nodes can exist. Nodes cannot share servers, storage, or clients.