Impact on Deleting large Data from Azure Netapp Volume with snapshot

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Impact on Deleting large Data from Azure Netapp Volume with snapshot

Shivprasad Pawar, Vodafone 20

We are planning to do a deletion of data from Azure Netapp Files volume, which is 95% Full, I wanted to understand if there is any impact on delete large data at a given time, the volume has snapshot feature enabled.

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Answer 1

Hello @Shivprasad Pawar, Vodafone,

Welcome to Microsoft Q&A Platform. Thank you for reaching out & hope you are doing well.

I understand you have a question about deleting data from an Azure NetApp Files (ANF) volume that is currently 95% full and has snapshot functionality enabled.

When you delete a large amount of data from an ANF volume with snapshots enabled, the storage space is not released right away. This happens because snapshots use pointers that still refer to the deleted data blocks, keeping those blocks in use until every snapshot referencing them has been removed.

After deleting data, storage usage might not immediately decrease because snapshots need to be deleted, and space reclamation must be completed first. Deleting data generally has a minimal effect on performance. However, since your volume is already at 95% capacity, it’s important to keep an eye on it to prevent any capacity-related problems. Sometimes, it may be necessary to temporarily increase the volume size before performing large deletions to provide enough space for metadata and snapshot operations.

Key Suggestions for Improving Your Environment:

1. Review and update snapshot retention policies. Deleting older snapshots will free up space, but keep in mind that once deleted, snapshots cannot be restored.
https://learn.microsoft.com/en-us/azure/azure-netapp-files/snapshots-manage-policy

2. Track the volume usage metrics, including both capacity and inode usage, before, during, and after the deletion process.

3. Do not delete snapshots that are being used in ongoing restore or clone processes. Also, keep in mind that the latest backup snapshot can only be deleted when certain conditions are met.

https://learn.microsoft.com/en-us/azure/azure-netapp-files/snapshots-delete

https://learn.microsoft.com/en-us/azure/azure-netapp-files/backup-delete

Proactively managing snapshots and keeping track of utilization allows you to safely perform large deletions on your ANF volume.

Kindly let us know if the above helps or you need further assistance on this issue.

Please "Accept the answer" if the information helped you. This will help us and others in the community as well.

Answer 2

Shivprasad Pawar, Vodafone 20

@Anonymous Thank you, I have a 60 TB volume which is approx 95% full and plan to delete something about 5to 10 TB, do I still need to worry about meta data increase or will the 4 TB free space in the pool able to handle it.

Regards

Shiv

Anonymous

2025-09-04T15:03:40.7933333+00:00

Hello @Shivprasad Pawar, Vodafone,

Thank you for providing the details.

With a 60 TB volume at about 95% usage, you have roughly 3 TB of free space. Deleting 5–10 TB of data should not create metadata overhead problems, and the available space should be sufficient to handle the operation.

You should be able to proceed, but it’s ensured to monitor pool and volume usage during deletion. If you want an extra safety margin, consider temporarily increasing the volume size before starting.

Kindly let us know if the above helps or you need further assistance on this issue.

Answer 3

Shivprasad Pawar, Vodafone 20

Thank you @Anonymous We will keep a track of the space in using after deleting the data, is there any chance of Meta increasing after deleting data from the volume, I understand the subsequent snapshot space will start to reduce, we only have the required snapshot for last few days which get expired after retention period.

Anonymous

2025-09-04T10:39:11.5233333+00:00
Hello @Shivprasad Pawar, Vodafone,
Good day

Yes, it's possible for metadata usage to temporarily rise when you delete large amounts of data from an Azure NetApp Files (ANF) volume. This occurs because the file system must update and track the changes from the deletion. Typically, the increase is minor compared to the total data volume, but it can be more noticeable on volumes that are already heavily used, such as yours at 95% utilization.

Important points to remember:

1. The increase in metadata is only temporary: This happens while the deletion process is underway, and usage levels will gradually stabilize.

2. Snapshots continue to reference blocks that have been deleted: Because snapshots are retained for only a few days, space from deleted blocks will be gradually recovered as older snapshots are removed based on your retention policy.

Suggested approach: If you’re planning a large deletion, it’s important to make sure there’s enough free buffer space. You can do this by temporarily increasing the volume size or adjusting snapshot retention, which helps ensure that metadata and deletion tasks finish smoothly without hitting capacity limits.

To sum up, metadata usage might increase a bit after deletions, but with your short retention period and regular monitoring, the space will be reclaimed as snapshots expired.

Kindly let us know if the above helps or you need further assistance on this issue.

Please "Accept the answer" if the information helped you. This will help us and others in the community as well.

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Impact on Deleting large Data from Azure Netapp Volume with snapshot

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