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Symantec NetBackup De-Duplication & SLP issue

Created: 03 Feb 2014 | 3 comments

Hi Friends,

I have a typical issue with the Netbackup De-duplication backup and SLP issue. I am not sure whether I have setup the De-duplication correctly and looking forward for your support. Below are the brief details of a setup.

NetBackup Master Server - NBU (running on Windows 2008 R2 SP2) 

NetBakcup Media Server -  NBU 5320 Appliance & only enabled the De-duplication (backend usable De-dupe size around 4.3TB). This has only storage Unit (STU_DD_UNIT)  & tape storage Unit - srv11100-hcart2-tld0

NetBackup Clients - Windows 2008 R2 SP2 (with Exchange 2010, SQL 2008, AD etc) 

Policy 1- Exchange-Daily

No SLP policy - the backup is directly taken to disk storage unit STU_DD_UNIT

Policy 2 - Exchange-Monthly   

SLP Policy - Monthly-Exchange  (Retention on De-duple Disk 6 months & duplication on tape 1 year). No Data Classification 

Policy 3 - Exhchange-yearly

SLP Policy - Yearly-Exchange (Retention on De-duple Disk 1 year & duplication on tape 3 years). No Data Classification 

I have run the validation check in SLP policy and there is not listed problems.  But when I run the backup randomly sometime it runs the Monthly-Exchange SLP policy or sometime Yearly-Exchange policies for the Exchange-Monthly backup policy. 

Just would like to have an idea, whether I have setup things correctly. Below are my queries

1) Can we have more the one Storage Life Cycle Policies on single disk storage Unit (de-duplication)?

2) if we can have multiple SLP on disk STU, then can we have the different retention for different policies for the same server?

3) since the different policies will have the different retention on Disk and Tape, will the de-duplication engine have an issue to expire the images, which have multiple retention for the same image?

4) If all the above are not expected setup for the de-dupe and SLP, then what will be the best practice for staging backup. We want to have the disk backup and then stage it to tape (disk and tape will have different retention for seperate policies as mentioned in above example).

5) What is the best practice to have de-duplication? Client Side or Server Side? since we use the NBU 5230 appliance, we are currently using Server side de-duplication. 

Appreciate your help and support on this. 



Operating Systems:

Comments 3 CommentsJump to latest comment

Yogesh.Jadhav's picture


1. Multiple SLP's can be configured using a single disk storage unit according to your need and requirment. 

2. After configuring SLP's they are used at policy level and not at server level. So you don't need to worry about the retention by/for server. For different retention make sure you have a different SLP as this is the recommended setting for efficient way/managment/behaviour of SLP duplication, doing this you will duplicate the same retention backup on the same tapes (if you are not allowing backups of different retention spanning on single tape)

 Basically your question 2 has nothing to do with SLP, in NetBakcup retention is defined at policy level and not for servers.

3. Duplication creates a copy of a backup image and Netbackup tracks the number of copies and its retention. Netbackup itself will delete the copies.

4. For ans, refer above explanation

5. Its debatable question, for now I would say server side deduplication would be better.

Thanks & Regards

Yogesh Jadhav
RamNagalla's picture

when I run the backup randomly sometime it runs the Monthly-Exchange SLP policy or sometime Yearly-Exchange policies for the Exchange-Monthly backup policy.

so how you are running the bakup.. are you triggering the backups maually or Scheduled them?

 please post the output of below command

bppllist <policyname> -L  for all policies  that are in question...

sriramrane's picture

Thanks Yogesh and much appreciated your support. 

I just have one more query here.

We have set the SLP like e.g.  Montly - backup on the disk (6 months retention) duplication to tape (1 year retention).  As mentioned in previous point #2, according to you the SLP need to have a single retention policy, whereas I have multiple retention policy for both Disk and Tape within same policy. Will it make any difference?