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Extended retention or not?


Userlevel 4
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Hello,

Sorry I can’t correct the title are/or :)

On a Storage policy that has deduplication enabled I have this message and I understood why.

My question is :

can I unselect the Extended Retention Rule 1 set for 90 days

and increase the basic one to for example to 90 days, if yes, how many cycle is good to have for 90 ?

 

 

 

Thanks

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Best answer by Sean Crifasi 5 May 2021, 17:23

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5 replies

Userlevel 6
Badge +14

Hi @Bloopa ,

In terms of calculating the Cycles, how frequently does your Plan/Schedule run a Full or Synthetic Full backup? (Weekly/Bi-Weekly/Monthly)

i.e. How many cycles fit into the 90-day period? and how many of these do you need to keep to maintain your RPO? - do you need to keep incremental’s for 90 days?

 

Best Regards,

Michael

Userlevel 4
Badge +14

@MichaelCapon 

Q :In terms of calculating the Cycles, how frequently does your Plan/Schedule run a Full or Synthetic Full backup? (Weekly/Bi-Weekly/Monthly)

A : incr daily, and synthetic full 1 per week.

I will give you a real example

for GOLD SLA for example, we should have a storage policy configured like this:

14 days for daily

56 days for weekly full

and 13 month for monthly full

the problem is when dedup is enabled, it complains about DDB size growth.

What is the solution to achieve that ?

 

Userlevel 7
Badge +23

@Bloopa , the cycle count it really just a catch to ensure you have X number of Fulls on media no matter what.

If a given full and all of its Incrementals are 90 days old, it will (generally) prune as long as you have X Fulls/cycles on that same copy.

So you can just put the number of Fulls you expect to have within 90 days and likely be fine (let’s say 12 fulls in 90 days).

You’ll only see issues if a client missed a full (which is the point, really).  You’ll see jobs much older than 96 days (90 days plus 6 days of Incrementals) which will tell you to take a look.

This post from a few months back has a link to a VERY informative video I highly recommend:

ps I edited your title for you :nerd:

Userlevel 4
Badge +9

Hi @Bloopa 
 

If I’m understanding correctly, you have a incremental backup run daily and synthetic full run weekly.

  • I would recommend setting basic retention to 14 days
    • With 1 cycle retention chosen, after the next synthetic full runs the previous cycle would meet retention when the latest incremental of the previous cycle has met its basic day retention
    • All jobs within the cycle must meet retention before any job in the cycle will become prunable
    • If you set 2 cycle basic retention then you would retain 2 cycles of backups and the first cycle would become prunable after a third has run and basic days is met for the latest backup of that first cycle.
    • A higher cycle count will allow you to retain additional cycles of the backups but may cause the backups to exceed your desired basic retention days as it will need to ensure all backups in the cycle have met basic days retention in addition to meeting the cycle retention
  • It is true that adding additional extended retention to the primary storage policy copy can lead to an increase in size
  • When you are intending to achieve an extended retention it is advised to create additional selective copies for this
  • https://documentation.commvault.com/commvault/v11/article?p=11919.htm
    • For deduplication storage policy copy, a message appears that tells you that enabling extended retention rules on a deduplicated copy might increase the DDB size.

      Click No and create a selective copy with deduplication for each selective criteria (for example, weekly, monthly, and so on) and set the higher basic retention period on each selective copy. For instructions, see Creating a Selective Copy.

  • https://documentation.commvault.com/commvault/v11/article?p=13907.htm
Userlevel 7
Badge +23

Moved the recent question to its own topic to better track the answer:

 

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