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Noob question - pruning principle

Noob question - pruning principle

From:
Abby Normal
Date:
2015-10-16 @ 15:07
Hello,

I don't understand the principle how the pruning works so please can you 
assist in the following example:

The first ever made backup which was created on server is full backup. 
If it is pruned due to defined retention policy, the second next backup 
will hold al the data from the first one + differences? The second 
backup holds only dedup data and references to first one and because of 
the references that point to the first backup the files from the first 
backup will not be deleted but instead they will be marked as included 
in the second backup? Right? And that logic is the same for every next 
backup if I got it right.

Regards,
Abby

Re: [attic] Noob question - pruning principle

From:
Michael Langley
Date:
2015-10-16 @ 15:12
Me either ???

On Fri, Oct 16, 2015 at 11:07 AM, Abby Normal <brutalgeisha@gmail.com> wrote:
> Hello,
>
> I don't understand the principle how the pruning works so please can you
> assist in the following example:
>
> The first ever made backup which was created on server is full backup.
> If it is pruned due to defined retention policy, the second next backup
> will hold al the data from the first one + differences? The second
> backup holds only dedup data and references to first one and because of
> the references that point to the first backup the files from the first
> backup will not be deleted but instead they will be marked as included
> in the second backup? Right? And that logic is the same for every next
> backup if I got it right.
>
> Regards,
> Abby

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Re: [attic] Noob question - pruning principle

From:
Leo Famulari
Date:
2015-10-16 @ 16:44
You are thinking that Attic is an incremental backup system, which it is 
not. It is a snapshot backup system.

The backups are deduplicated in a content addressed store. All the data 
goes into this store, in chunks. Each "backup" is just a list of files and
the chunks that the files are composed of.

When you prune a backup, the only chunks that are deleted are those chunks
that are not referenced by any other backups.

So each backup is a "full" backup in some sense. There are no incremental 
diff backups.


On October 16, 2015 11:12:40 AM EDT, Michael Langley <mlangley@ycp.edu> wrote:
>Me either ???
>
>On Fri, Oct 16, 2015 at 11:07 AM, Abby Normal <brutalgeisha@gmail.com>
>wrote:
>> Hello,
>>
>> I don't understand the principle how the pruning works so please can
>you
>> assist in the following example:
>>
>> The first ever made backup which was created on server is full
>backup.
>> If it is pruned due to defined retention policy, the second next
>backup
>> will hold al the data from the first one + differences? The second
>> backup holds only dedup data and references to first one and because
>of
>> the references that point to the first backup the files from the
>first
>> backup will not be deleted but instead they will be marked as
>included
>> in the second backup? Right? And that logic is the same for every
>next
>> backup if I got it right.
>>
>> Regards,
>> Abby

Re: [attic] Noob question - pruning principle

From:
Abby Normal
Date:
2015-10-16 @ 17:33
Thank you :)

Regards,
Abby
On Oct 16, 2015 6:45 PM, "Leo Famulari" <leo@famulari.name> wrote:

> You are thinking that Attic is an incremental backup system, which it is
> not. It is a snapshot backup system.
>
> The backups are deduplicated in a content addressed store. All the data
> goes into this store, in chunks. Each "backup" is just a list of files and
> the chunks that the files are composed of.
>
> When you prune a backup, the only chunks that are deleted are those chunks
> that are not referenced by any other backups.
>
> So each backup is a "full" backup in some sense. There are no incremental
> diff backups.
>
>
> On October 16, 2015 11:12:40 AM EDT, Michael Langley <mlangley@ycp.edu>
> wrote:
> >Me either ???
> >
> >On Fri, Oct 16, 2015 at 11:07 AM, Abby Normal <brutalgeisha@gmail.com>
> >wrote:
> >> Hello,
> >>
> >> I don't understand the principle how the pruning works so please can
> >you
> >> assist in the following example:
> >>
> >> The first ever made backup which was created on server is full
> >backup.
> >> If it is pruned due to defined retention policy, the second next
> >backup
> >> will hold al the data from the first one + differences? The second
> >> backup holds only dedup data and references to first one and because
> >of
> >> the references that point to the first backup the files from the
> >first
> >> backup will not be deleted but instead they will be marked as
> >included
> >> in the second backup? Right? And that logic is the same for every
> >next
> >> backup if I got it right.
> >>
> >> Regards,
> >> Abby
>
>