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Retention rules question

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Forum Member
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I have some difficulties to understand how the Retention rules are working - "by backup age".

e.g.: by backup age, month 6, weeks 4 - what does this mean.

 

Many thanks for your help in advance

 

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Regular Poster
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Comments: 291

#1

Hi

"by backup age" means how long to keep backups created by the backup plan. Product after the backup checks the creation date of the backups and delete backups which creation date is older than specified value.

By default, By default, the retention rules are specified for each backup set separately.

You can read this in the documentation.

 

Beginner
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Comments: 8

#2

Hi,

I would like to know more about retention. I found that the default setting of "Clean up by backup age" is:

Monthly: 6 months

Weekly: 4 weeks

Daily: 7 days

So, when will the backup be deleted by the retention rule, 7 days after, 4 weeks after or 6 months after?

For your reference, the backup scheme for it is "Always incremental (single-file)" with weekly scheduled backup

Support specialist
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Comments: 1017

#3

Hello Ernest,

thank you for posting your question on Acronis forums!

This retention rules scheme will be applied as described to Monthly full, Weekly differential, Daily incremental (GFS) scheme. 

Since there are no differentials created in your case with Always incremental (single-file) scheme, it will work the following way:

- once a week an oldest incremental backup is marked for deletion (but not deleted since other incrementals depend on it!);

- nothing happens once in 4 weeks (since there are no differentials);

- once in 6 months your full backup is consolidated with all incrementals that are marked for deletion.

Beginner
Posts: 1
Comments: 8

#4

Hello Maria

Thank you for answering my question. Your answer has clarified my confusion.

But I am still having a few questions with Acronis backup.

1. What does "marked for deletion" mean? Will the backup file (which is marked for deletion) be deleted immediately? If not, when will it be deleted?

2. If I select the backup scheme of "Always incremental (single-file)"would it still create a full backup file in the first backup?

3. Followed by question 1, If it will create a full backup file in the first backup, according to what you have mentioned "once a week an oldest incremental backup is marked for deletion (but not deleted since other incrementals depend on it!)", the second backup (which should be the oldest incremental backup) would not be deleted and only the third and afterward backup would be deleted. Is it correct?

4. As the backup scheme is selected as "Always incremental (single-file)", there should be no other full backup other than the first backup. "once in 6 months your full backup is consolidated with all incrementals that are marked for deletion", if the full backup with corresponding incremental backup are deleted by the retention policy, does it mean that I need to re-backup all the data (which has been backed up before)?

In addition, I would like to know that is there any difference between Acronis True Image 2020 and Acronis Backup 12.5 for the mechanism of retention rule?

Support specialist
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#5

Hello Ernest.

1. What does "marked for deletion" mean? Will the backup file (which is marked for deletion) be deleted immediately? If not, when will it be deleted?

When a new full backup is created, a previous full backup will be consolidated with all incrementals that are "marked for deletion".

2. If I select the backup scheme of "Always incremental (single-file)"would it still create a full backup file in the first backup?

The initial backup is always full and all subsequent incremental backups are saved to a single .tib file.

3. Followed by question 1, If it will create a full backup file in the first backup, according to what you have mentioned "once a week an oldest incremental backup is marked for deletion (but not deleted since other incrementals depend on it!)", the second backup (which should be the oldest incremental backup) would not be deleted and only the third and afterward backup would be deleted. Is it correct?

In "Always incremental" scheme non of these backup will be deleted since they all are the content of a single backup file. They will be consolidated inside this file with the first full backup. Once the next 6 months have passed, the previously consolidated backup will be again consolidated with the next chain of "marked for deletion" incrementals.

4. As the backup scheme is selected as "Always incremental (single-file)", there should be no other full backup other than the first backup. "once in 6 months your full backup is consolidated with all incrementals that are marked for deletion", if the full backup with corresponding incremental backup are deleted by the retention policy, does it mean that I need to re-backup all the data (which has been backed up before)?

No, you do not need to re-backup all the data. Please see the previous reply.

In addition, I would like to know that is there any difference between Acronis True Image 2020 and Acronis Backup 12.5 for the mechanism of retention rule?

There is no "Always incremental (single-file)" backup scheme in Acronis True Image 2020. Please see cleanup rules settings available for the custom backup scheme in Acronis True Image 2020: https://www.acronis.com/en-us/support/documentation/ATI2020/index.html#16143.html

Beginner
Posts: 1
Comments: 8

#6

Hello Maria,

I have further read some posts and articles about incremental backup and retention policy. I found that actually except backup scheme "Single-file backup format (always incremental backup)" (which can only apply to some backup items), incremental backup can only be deleted with the full backup (just like what you mention, latest incremental backup is dependent on the older incremental backup). So what is the meaning/usage of setting the retention rule for incremental backup since it can only be deleted with the full backup?

(Even if I set up the retention rule for it, it will not be deleted until the full backup is going to be deleted by retention rule)

Support specialist
Posts: 0
Comments: 1017

#7

Hello Ernest.

"Single-file backup format (always incremental backup)" backup format leverages the speed of the incremental backup method, while avoiding its main disadvantage–difficult deletion of outdated backups. The software marks the blocks used by outdated backups as "free" and writes new backups to these blocks. This results in extremely fast cleanup, with minimal resource consumption.

Forum Moderator
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#8
Ernest Chan wrote:

So what is the meaning/usage of setting the retention rule for incremental backup since it can only be deleted with the full backup?
(Even if I set up the retention rule for it, it will not be deleted until the full backup is going to be deleted by retention rule)

Hello Ernst,

the below article is for an older product, but the main features of the always-incremental archive are the same. I'd recommend taking a look at the Introduction part, where the process of cleanup is described in detail  https://kb.acronis.com/content/47184   

Beginner
Posts: 1
Comments: 8

#9

Hi,

Thank you for the clear clarification of "always incremental backup". However, actually what I want to focus is backup scheme other than "always incremental backup" (as I found that "always incremental backup" is not an option for file/folder backup). 

Let me provide an example for my question:

A backup plan is set up as following:

1. Set up Backup scheme as weekly full, daily incremental with backup schedule in picture 1. 

2. Set up How long to keep as Weekly: 2 weeks, Daily: 1 Days in picture 2.

In above case, how will the incremental backup be deleted?

1. Incremental backup will be deleted after one day (as it only keep 1 day by the setting)?

2. Or all incremental backups will be consolidated with full backup after two weeks and be deleted with the full backup (according to my understanding to Maria reply in #3)?

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Beginner
Posts: 1
Comments: 8

#10

Is there any update to my question? Do I need to further clarify my question?

Regular Poster
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Comments: 111

#11

Hello Ernest!

Here is a breakdown of what happens on each day to the best of my knowledge, assuming the backup always succeeds. There is a conflict with you attached picture (weekly 4, daily 7) and your question, so I'll assume this:

1. Set up Backup scheme as weekly full, daily incremental with backup schedule in picture 1. 

2. Set up How long to keep as Weekly: 2 weeks, Daily: 1 Days in picture 2.

  • Week 1
    • day 1 - Mo: Full-1
    • day 2 - Tu: Full-1-Inc-1 
    • day 3 - We: Full-1-Inc-2, Full-1-Inc-1 is marked for deletion
    • day 4 - Th: Full-1-Inc-3, Full-1-Inc-2 inc is marked for deletion
    • day 5 - Fr: Full-1-Inc-4, Full-1-Inc-3 inc is marked for deletion
    • day 6 - Sa: Full-1-Inc-4 inc is marked for deletion
    • day 7 - Su: -
  • Week 2
    • day 8 - Mo: Full-2, Full-1-Inc-1 to Full-1-Inc-4 consolidated into Full-1 
    • day 9 - Tu: Full-2-Inc-1 
    • day 10 - We: Full-2-Inc-2, Full-2-Inc-1 is marked for deletion
    • day 11 - Th: Full-2-Inc-3, Full-2-Inc-2 inc is marked for deletion
    • day 12 - Fr: Full-2-Inc-4, Full-2-Inc-3 inc is marked for deletion
    • day 13 - Sa: Full-2-Inc-4 inc is marked for deletion
    • day 14 - Su: -
  • Week 3
    • Day 15 - Mo: Full-3, Inc-1 to Inc-4 consolidated into Full-2, Full-1 deleted
    • ...

-- Peter

Beginner
Posts: 1
Comments: 8

#12

Hi Peter,

Thank you for your great explanation. I would like to confirm my understanding to your explanation. Does "mark for deletion" mean that the incremental backup will not be deleted immediately even if it is expired? If yes, is it just like what you have shown, the incremental backups will consolidate with the full backup when the second full backup is created? Refer to

Week 2

  • day 8 - Mo: Full-2, Full-1-Inc-1 to Full-1-Inc-4 consolidated into Full-1

And finally, the full backup (with consolidated incremental backups) will be deleted when the full backup is expired? refer to

Week 3

  • Day 15 - Mo: Full-3, Inc-1 to Inc-4 consolidated into Full-2, Full-1 deleted

 Appreciate if you can answer my question.

Regular Poster
Posts: 8
Comments: 111

#13

Hello Ernest!

Does "mark for deletion" mean that the incremental backup will not be deleted immediately even if it is expired?

That's right. On Day 3, Day 2 incremental is now ready to be deleted, but since day 3 incremental depends on it, it can't be deleted yet. 

With this retention scheme you should expect 4 incremental and 2 full backup to coexist (at most) per backed up machine.

And finally, the full backup (with consolidated incremental backups) will be deleted when the full backup is expired?

As your retention rule says 2 weeks for weeklies, On day 15, the backup made on day 1 is now 2 weeks old, so can be deleted.

I'm less sure about the exact time Full-1 would be deleted, since exact time the backups run, the day that's counted for weekly backups, and whether you apply retention before or after backup all affect the outcome.

-- Peter

 

Beginner
Posts: 1
Comments: 8

#14

Thanks for your help. Peter.