Retention and Incrementals

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Retention and Incrementals

Veeam Logoby McClane » Fri May 06, 2016 11:06 am

Hi,

I have a questions about the retention period of a media pool that is used for incrementals.
I set it to 2 weeks because after two week I only keep the full backup for a month.
On monday the first tapes reach the end of retention. So, if they will be reused then, the incrementals of the following days have a broken backup chain, so they could be reused, too.
How does Veeam handle that? And if not, how can I get a list of tapes that does not belong to a valid backup chain but are still in retention?

Thanks,

Manuel
McClane
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Re: Retention and Incrementals

Veeam Logoby Shestakov » Fri May 06, 2016 12:08 pm

Hi Manuel,
You need to set according schedule and protection period for the tapes.
I.e. protection period should be longer than the chain age.
Shestakov
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Re: Retention and Incrementals

Veeam Logoby McClane » Fri May 06, 2016 12:21 pm

That's not what I meant. I am not afraid that incrementals are being overwritten before the chain expires. It's the other way around.

I have synthetic fulls on saturday and incrementals from sunday to friday.
I have 2 pools, one for fulls one for incrementals. The full pool has a retention of 1 month. The incrementals two week. So I get 2 weeks with daily incrementals and then 4 weekly fulls.
After 2 weeks, when the first incremental expires, it can be overwritten. But the tapes of the following days are still in retention for the rest of the week and can't be used.
Doesn't matter how long I set the retention, I will need minumum 6 extra tapes, because the retention does not take in account that one backup in the incremental chain is already out of retention. Or does it?
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Re: Retention and Incrementals

Veeam Logoby Shestakov » Fri May 06, 2016 12:38 pm

Thanks for the clarification.
So the pain is that once the tape with the first increment is overwritten, other 4 tapes with increments are still protected despite those increments are already useless. Is that correct?
If a tape can fit more than 1 increment, I would suggest to create a new media set not every day, but once a week (Saturday) and set 2 weeks retention. It will also allow you to use less tapes, so the space will be used more efficiently.
Thanks!
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Re: Retention and Incrementals

Veeam Logoby McClane » Sat May 07, 2016 12:48 pm

I can't do that. Because I need to export the daily increments offsite by our policy. What is a disaster backup good for, if the backups burn with the rest of the building?
And it's even worse then I thought. Veeam does not show me that the backup chain is broken. I can still select backup points for restore that are taken past the already deleted incremental tape. And more worse, when I click next the error message says it can't find the full backup... that's a major design flaw. I should not be able to select an incremental point for a VM restore if there are incrementals missing.
And it should mark incremental backups if the chain is broken. And also expire tapes in the chain if there are only broken chains on them.
We have a relativly small environment. I wonder how bigger companies can keep track of the tapes with that tape management.
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Re: Retention and Incrementals

Veeam Logoby Shestakov » Mon May 09, 2016 6:41 am

Incremental backup are usually used for the short-term retention while GFS backups are historical. Naturally if chain of backups is broken latest points are not restorable. That`s the cost you pay for saving space.
I really like your idea to free up protected tapes if older increments of the chain are already rewritten. We will discuss it with developers.
Thanks for your feedback!
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