moving dedup to client

[manatee]

NBU 7.6.0.3, Windows/Solaris clients, Linux master/media server

i'm troubleshooting a performance issue with my backups and someone suggested that I:

• Allow multiple data streams
• Enable client-side deduplication

i also need to set in the master server/client attributes the location of the deduplication. there are three options there: server side deduplication, prefer client-side deduplication, always client-side deduplication.

i tried the help button but somehow that crashed my NBU console. so, what's the advantage of using "prefer client-side deduplication" over "always use client-side deduplication"?

[Marianne]

Before we get into Host Properties settings - which type of dedupe is being used in your environment?
Client side dedupe is only supported with NBU MSDP.

[manatee]

please how can i check for NBU MSDP? i know my master server is also a media server and i have a 9TB partition where we keep backup images before being sent to tape library.

[Marianne]

If the diskpool type is PureDisk, then you have MSDP.

To answer your question:

"prefer client-side deduplication" means that client-side dedupe will be tried first. If it is not possible for some reason, NBU will switch to Media Server dedupe.

"always use client-side deduplication" will cause the backup to fail if client-side dedupe is not possible.

If you are still using 3 day retention on dedupe disk, then switching to client-side is not going to be of any benefit. Or very low benefit, as good dedupe rates need at least 2 week retention on dedupe disk.

[manatee]

that 9TB partition type is PureDisk. so that's good.

actually i only have 1  day retention to conserve space as i backup a lot of data. i can't afford for them to stay on disk for more than 2 days.

it is for backup performance that i'm looking at multiple streams and client-side dedups.

if i'm going to do client-side dedups and have a disk retention of less than 2 weeks, how is it not beneficial? the idea is to offload the dedup work from server to client, then send only to server what needs to be backup (after dedup process is done).

[Marianne]

You will get little or no dedupe with 1 day retention. Media server dedupe or client-side dedupe.

Everything will be backed up in full each day.

We have been through this topic some time ago....  You need to increase the dedupe volume to utilize dedupe advantage.

[manatee]

a bit of hardheaded there my part. tonight i'll increase the disk retention to one week and will see if any change. server-side dedup.

[watsons]

1. Allow multiple data streams
2. Enable client-side deduplication

I would apply #1 if a single stream of backup is too slow and exceeds my backup window. 

For #2, it's not as straightforward. Client-side deduplication basically mean the dedup process happens on the client, no extra installation required but you gotta make sure the client H/W spec (resources) is up to it, otherwise enabling it make lead to worse scenario (resources of client max. up and bring down applications of the client itself - which can be disastrous!)

Requirement, please read: 
https://vox.veritas.com/t5/NetBackup/Host-requirements-for-client-side-deduplication/td-p/683950

Client-side deduplication is mostly implemented if there is a slow link (e.g. WAN) between your media server and client, and you don't want to flood the bandwidth, so you have the dedup done on the client and send as little data as possible to the media server.