what is the retention policy in NetBackup integrating with Data Domain?

[nbmagic]

Suppose I am using Data Domain as STU in NBU with Data Domain boost. What retention policy should be look like? I may not quite understand it conceptually, but is retention policy applicable if I using Data Domain? I read some documents, and retention policy seem not configured. I don't see any where to define how long I should keep daily, weekly or monthly backup. I must be missing something here.

Please shed some lights on this concept.

[Omar_Villa · Accepted solution]

It really depends of you business needs but considering disk is limited normally I see something between 7 to 60 days rentention on disk and anyhing greater is usually duplicated to tape using SLP's. Just think that highier the retention more disk space u will need.

[nbmagic]

Understood.

I was thinking why in the document I have read about NBU&Data Domain, there seems no any retention policy needs to be defined. So, I am wondering with Data Domain in play, if this is going to change the way we usually handle retentions, or if there is any different in retention comparing DM, and those without DM?

[Omar_Villa]

If you are talking about retention levels at datadomain level u can ignore that and configure all your retentions in nbu.

[Marianne]

I was thinking why in the document I have read about NBU&Data Domain, there seems no any retention policy needs to be defined.

Really? Which document are you reading?

It is impossible to define backup policies in NBU without retention levels. 

Retention must be specified in the policy schedules or else in SLPs.