Azure Storage Blob Huge Soft-deleted Missing

Question

We have a storage account configured with soft-delete for 360 days and versioning disabled. The blob container is mounted in AKS via the official CSI Driver feature. The issue we are seeing is that we have 64TB of soft-deleted data, but cannot see this information in the Azure Storage Explorer or via the storage API, it only shows 188 soft-delete blobs worth 50GB. We generate ~1.4GB every week (256mb files) and soft-delete the old files after it reaches 1000 in total, it's been 8 months and it's not possible to reach 64TB in total soft-deleted.

We have requested an Inventory Report on blobs and hopefully that will gives more information.

Are there other debug options we can apply?

Answer 1

@Ben C Thank you for reaching out to Microsoft Q&A. We apologize for the delay in responding to your issue.

I understand that you have 64 TB of soft deleted data but cannot see the same in Storage Explorer or Storage API. Where do you see that you have 64 TB of soft deleted data? Are you saying this is expected or is this incorrect?

You can use Azure Monitor and look for monitoring logs such as Storage Delete to understand the behavior of Soft Delete operations on your data. Here is the link for the same that details more information on the same and also steps on setting it up- https://learn.microsoft.com/en-us/azure/storage/blobs/monitor-blob-storage?tabs=azure-portal

Create Diagnostic settings- https://learn.microsoft.com/en-us/azure/azure-monitor/essentials/diagnostic-settings?tabs=portal

Hope this helps. If you require further assistance, please let me know. Thank you!

Answer 2

@Ben C Welcome to Microsoft Q&A Forum, Thank you for posting your query here!

Based on your scenario, We need to work closer on this issue. I would recommend you to contact support, so If you have a support plan, I request you file a support ticket, else please do let us know, we will try and help you get a one-time free technical support. In this case, could you send an email to AzCommunity[at]Microsoft[dot]com referencing this thread as well as your subscription ID. Please mention "ATTN subm" in the subject field. Thank you for your cooperation on this matter and look forward to your reply.

Additional information:

When you enable blob soft delete for a storage account, you specify a retention period for deleted objects of between 1 and 365 days. The retention period indicates how long the data remains available after it's deleted or overwritten. The clock starts on the retention period as soon as an object is deleted or overwritten.

While the retention period is active, you can restore a deleted blob, together with its snapshots, or a deleted version by calling the Undelete Blob operation. The following diagram shows how a deleted object can be restored when blob soft delete is enabled:

You can change the soft delete retention period at any time. An updated retention period applies only to data that was deleted after the retention period was changed. Any data that was deleted before the retention period was changed is subject to the retention period that was in effect when it was deleted.

Attempting to delete a soft-deleted object doesn't affect its expiry time.

If you disable blob soft delete, you can continue to access and recover soft-deleted objects in your storage account until the soft delete retention period has elapsed.

Blob versioning is available for general-purpose v2, block blob, and Blob storage accounts. Storage accounts with a hierarchical namespace aren't currently supported.

Version 2017-07-29 and higher of the Azure Storage REST API support blob soft delete.

Please let us know if you have any further queries. I’m happy to assist you further.

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