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NetBackup™ Deduplication Guide

Last Published: 2022-03-28

Product(s): NetBackup (10.0)

About client-side deduplication

Client-side deduplication or Client Direct is an easy way to improve the performance of your backups to an MSDP target. Part of the innovated MSDP deduplication architecture is the use of a distributed, plugin-based fingerprinting service. Instead moving all the data to the storage server before it's deduplicated, the fingerprinting, compression, and encryption can all be performed right on the source. This leads to ideal optimization and acceleration, with minimal network overhead. In the past, with lower power CPUs compared to today's technology, Client Direct was only recommended for systems with high-power processors. Testing has shown that the effect to a client system is very low. As a result, the use of client-side deduplication is encouraged for wider, more regular use.

The three Deduplication Location options for MSDP are:

Always use the media server - All data is sent to the media server and the plug-in deduplication occurs on that server before the MSDP storage target is written to.
Prefer to use client-side deduplication - At the beginning of a backup, a quick test is performed to verify that the client can successfully use client-side deduplication. If the test fails, the job falls back on the use of server-side deduplication.
Always use client-side deduplication - The backup job explicitly uses client-side deduplication. If the functionality does not work, the job fails.

Note:

When deduplication is performed on the server side or the client side, the same plug-in library is loaded. As a result, the deduplication capabilities and results are not different.

How to enable client-side deduplication

By default, deduplication from the client side is disabled, and must be enabled on a per host basis. From a policy perspective, the functionality can be explicitly disabled. If you include the command line, there are three ways to control this setting.

The three ways to control the setting are as follows:

To enable client-side deduplication, you must add the client to the clientDB and then setting the client to Prefer to use client-side deduplication.
- To do this operation in the Java GUI, first open the master server host properties, and then open Client attributes section.
- Select Prefer to use client-side deduplication from the Deduplication location drop-down and select OK.

To enable client-side deduplication the command line, use with the bpclient command with the -client_direct option. Refer to the following example for -client_direct usage:

-client_direct <0=Deduplicate on the media server or 
Move data via media server,
1=Prefer to use client-side deduplication or
Prefer to move data direct to storage,
2=Always use client-side deduplication or
Always move data direct to storage>

The following is an example of how to use the bpblient command with the -client_option to add the client to the clientDB and enable Prefer to use client-sided deduplication:

UNIX:

/usr/openv/NetBackup/bin/admincmd/bpclient 
-client <CLIENT_NAME> -add -client_direct 1

Windows:

\Program Files\Veritas\NetBackup\bin\admincmd\bpclient.exe
 -client <CLIENT_NAME> -add -client_direct 1

You can use a script to enable client-side deduplication. The following is an example of a script that checks if the client exists and if not, it adds the client and enables Prefer to use client-sided deduplication. If the client already exists, the script updates the setting to Prefer to use client-sided deduplication.

Script example:

> export CLIENTLIST = "client1 client2 client3 client4"
#!/bin/bash
for CLIENT in $CLIENTLIST
do
/usr/openv/NetBackup/bin/admincmd/bpclient 
-client $CLIENT -l &> /dev/null 
EXISTS=$?
if [ $EXISTS = "227" ]
then
echo "$CLIENT not found, adding and enabling client direct"
/usr/openv/NetBackup/bin/admincmd/bpclient 
-client  $CLIENT -add -client_direct 1 ;
else
echo "Updating $CLIENT to use client direct"
/usr/openv/NetBackup/bin/admincmd/bpclient 
-client  $CLIENT -update -client_direct 1 ;
fi;
done

Note:

To disable the use of client-side deduplication on a per policy basis, you must select Disable client-side deduplication for each policy in the Attributes tab.