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:
- 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.
- 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.
- 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.
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
clientDBand then setting the client to .To do this operation in the Java GUI, first open the master server host properties, and then open Client attributes section.
Select from the drop-down and select .
To enable client-side deduplication the command line, use with the bpclient command with the
-client_directoption. Refer to the following example for-client_directusage:-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
clientDBand enable :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 . If the client already exists, the script updates the setting to .
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 for each policy in the Attributes tab.