Share via

VM disk backup

Priyadarshini 60 Reputation points
2026-04-21T05:48:18.7866667+00:00

I added a disk VM and I backed up my VM now how can I backup new disk added and what is the retention back up points using backup policy.

Azure Backup
Azure Backup

An Azure backup service that provides built-in management at scale.

0 comments

Answer accepted by question author

  1. Suchitra Suregaunkar 13,785 Reputation points Microsoft External Staff Moderator
    2026-04-21T09:19:48.4866667+00:00

    Hello Priyadarshini

    Thank you for posting your query on Microsoft Q&A platform.

    When you attach a new data disk to an Azure VM that is already protected by Azure Backup, the new disk is automatically included in the next scheduled backup job no manual action is required, as long as selective disk backup is not configured to exclude it.

    • Initial Replica: During the next backup job, Azure Backup takes a full snapshot (Initial Replica) of the newly added disk, while existing disks continue with their normal incremental backup chain.
    • Selective Disk Backup (if enabled):
      • If you are using the Standard policy, selective disk backup via the Azure portal is limited to the OS disk only. You can use Azure CLI or PowerShell to include/exclude specific data disks by their LUN.
      • If you are using the Enhanced policy, you can explicitly include or exclude specific data disks from the Azure portal, and optionally choose to include disks added in the future.
    • Verification: To confirm the new disk is being backed up, go to the Recovery Services vault → Backup Items → Azure Virtual Machine → select your VM and check the disk details in the latest recovery point.
    • If selective disk backup is enabled and the new disk is excluded, it will not be backed up. Review your backup configuration to ensure the new disk is included.
    1. Retention of Backup Points Using Backup Policy:

    Azure VM backup policy supports the following maximum retention ranges.

    • Retention of daily backup points: 9999 days
    • Retention of weekly backup points: 5163 weeks
    • Retention of monthly backup points: 1188 months
    • Retention of yearly backup points: 99 years

    Additional notes:

    • The minimum retention for a daily backup point is 7 days.
    • To adjust retention, edit the VM's backup policy (Standard or Enhanced) in the Recovery Services vault and configure the daily/weekly/monthly/yearly retention ranges as needed.
    • With the Enhanced policy, you can schedule backups as frequently as every 4 hours (hourly frequency) and retain instant restore snapshots for up to 30 days.
    • If retention is extended, existing recovery points are marked and kept per the new policy. If retention is reduced, recovery points are marked for pruning in the next cleanup job.

    Reference:

    Thanks,

    Suchitra.

    1 person found this answer helpful.
    0 comments

1 additional answer

Sort by: Most helpful
Most helpful Newest Oldest
  1. Q&A Assist
    2026-04-21T05:48:30.4633333+00:00
    AI generated content. This question contains an answer created with AI from Q&A Assist. Learn more

    A newly added data disk on an Azure VM is backed up automatically by Azure Backup in the next scheduled backup, as long as selective disk backup isn’t configured to exclude it.

    Details:

    • When a new disk is attached to a protected VM, Azure Backup takes a full snapshot (Initial Replica) of that new disk during the next backup job.
    • Existing disks on the VM continue with their normal incremental backup chain.
    • If selective disk backup is enabled and the new disk is excluded, it won’t be backed up. With an Enhanced policy, it’s possible to explicitly include or exclude specific data disks and optionally choose to include disks added in the future.

    Retention of backup points using a backup policy:

    • Daily backup points: can be retained up to 9999 days.
    • Weekly backup points: can be retained up to 5163 weeks.
    • Monthly backup points: can be retained up to 1188 months.
    • Yearly backup points: can be retained up to 99 years.
    • For Azure VM backup policy, the minimum retention for a daily backup point is 7 days.

    To adjust retention, edit the VM’s backup policy (Standard or Enhanced) and configure the daily/weekly/monthly/yearly retention ranges as required.

    References:

Your answer

Answers can be marked as 'Accepted' by the question author and 'Recommended' by moderators, which helps users know the answer solved the author's problem.