Azure Backup Full

Question

Azure Backup Full

Handian Sudianto 7,441

If i have azure backup with retention daily 90 days, monthly 12 and yearly 3 then as i know azure will do the full backup on first intial, am i right? Let say 1st backup happen on 1st Jan then backup at 02 to the next 90 days is incremental?

How about monthly backup, still incremental or full?

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2 answers

Your answer

Answer 1

Yes. For Azure VM backups, the first backup is a full backup and subsequent backups are incremental.

For the scenario described:

If the first backup runs on 1 Jan, that first recovery point is the full backup.
The following scheduled backups, including the backups taken over the next 90 days, are incremental backups.

The monthly and yearly retention settings do not cause Azure Backup to take separate full backups. They are retention rules applied to recovery points created by the backup schedule.

Key points:

A backup policy has two parts: schedule and retention.
Retention is applied to backup points.
Monthly and yearly retention simply keep selected recovery points longer.
Each recovery point behaves like a full point for restore, so restoring an older point does not take more time than restoring a newer point.

So in practice:

Initial backup = full
Later scheduled backups = incremental
Monthly/yearly retained points = still based on those scheduled recovery points, not new full backups

Answer 2

Marcin Policht 107K MVP Volunteer Moderator

You are correct. In Azure Backup, the initial backup is a full backup, and all subsequent backups (whether they are daily, monthly, or yearly) are incremental backups. Even though Azure Backup only takes incremental data after day one, it uses an internal architecture that makes every recovery point behave like a full backup when you need to restore.

The monthly and yearly retention points do not mean Azure Backup performs a new full backup on those dates. Azure Backup continues to use the underlying incremental backup chain and retains the recovery point selected for monthly or yearly retention for the longer retention period. For example, if January 31 is selected as a monthly recovery point, Azure does not need to create a separate full backup specifically for January 31. That recovery point is retained according to the monthly retention policy. Similarly, a yearly recovery point is retained for the specified three years.

So conceptually, your policy would be: January 1 = initial backup, January 2 onward = incremental backups, while selected daily/monthly/yearly recovery points are retained for their respective retention periods. The important point is that "monthly backup" and "yearly backup" in the retention policy refer to how long selected recovery points are retained, not that Azure performs a separate full backup each month or year.

If the above response helps answer your question, remember to "Accept Answer" so that others in the community facing similar issues can easily find the solution. Your contribution is highly appreciated.

hth

Marcin

Handian Sudianto 7,441 Reputation points

2026-09-11T13:21:55.2066667+00:00

hi @Marcin Policht

So the daily incremental is independent? I mean if Jan 1 is full, Jan 2 incremental, Jan 3 is incremental.

The incremental of Jan 3 is a change between Jan 1 and Jan 3 or a change from Jan 2 to Jan 3?
Marcin Policht 107K Reputation points MVP Volunteer Moderator

2026-09-11T14:47:41.7366667+00:00

Jan 3's incremental backup represents the changes since the previous backup, Jan 2, not the cumulative changes since Jan 1. So conceptually:

Jan 1 = Full backup: A+B+C Jan 2 = Incremental: D+E (changes since Jan 1) Jan 3 = Incremental: F (changes since Jan 2) Jan 4 = Incremental: G+H (changes since Jan 3)

However, Azure Backup's incremental backup implementation is more sophisticated than simply storing a traditional sequential chain that must be replayed exactly as-is. Azure Backup maintains metadata and storage structures so that each recovery point can be restored as a complete point-in-time state. Therefore, if you restore Jan 3, Azure Backup reconstructs the Jan 3 state even though the underlying storage contains incremental changes.

If the above response helps answer your question, remember to "Accept Answer" so that others in the community facing similar issues can easily find the solution. Your contribution is highly appreciated.

hth

Marcin
Handian Sudianto 7,441 Reputation points

2026-09-12T01:09:14.5366667+00:00

hi @Marcin Policht

However if we restore to Restore Point (RP) on Jan 3 then incremental on Jan 2 is needed? I mean how if the incremental Jan 02 is corrupted, can we restore to the next RP after Jan 02?
Marcin Policht 107K Reputation points MVP Volunteer Moderator

2026-09-12T03:42:41.8066667+00:00

Azure Backup's incremental architecture is specifically designed so that recovery points are independently usable and do not operate like a simple traditional incremental chain where Jan 3 must replay Jan 1 → Jan 2 → Jan 3.

For Azure Backup, think of the recovery points as logically independent point-in-time states, even though Azure stores the underlying data incrementally. If Jan 1 is the initial full backup and Jan 2 and Jan 3 contain changes, Azure maintains the necessary underlying data so that the Jan 3 recovery point can be restored without requiring a healthy, sequential Jan 2 "backup file" in the traditional sense.

The underlying storage is optimized using incremental changes, but each recovery point is presented as a complete restore point. You should not interpret "incremental" as meaning "Jan 3 literally requires the Jan 2 recovery-point data to be replayed."

If the above response helps answer your question, remember to "Accept Answer" so that others in the community facing similar issues can easily find the solution. Your contribution is highly appreciated.

hth

Marcin