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Comment by comice | Hacker News Reader

"immediately raise a ticket with Azure Support, who were able to grab the resources from “somewhere” (I guess when you delete a resource in Azure, it’s still on a disk somewhere, for a while), and we got our database and backups back"

what the hell is Azure doing pretending to delete things?

How long do Azure keep your data after you think you've deleted it?

Is there a way to ensure data stored in Azure is actually destroyed when you ask for it to be destroyed?

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I can't speak to any specifics, but asynchronous behavior, including deletions, is very common in large distributed systems, and Azure I'd wager is no exception.

Update: I'd forgotten that even filesystems often do a soft delete. https://lwn.net/Articles/462437/

A bunch of high-profile resources have temporary soft-deletes - resource groups, managed SQL DBs, KeyVaults, Storage Accounts, and even subscriptions themselves. For some of these the undelete option is given to the user, for others you have to call support.

ah ok, phew! I guess the OP just didn't know about that - they seemed surprised it was recoverable!

Well it's not documented for resource groups, so their surprise is expected. The fact that it applies to resource groups is based on empirical evidence.

It's also not documented b/c Azure and AWS don't want to give promises about this being possible.

Tables in Azure Storage are an example of this -- the delete is performed asynchronously by a background thread some time later (just garbage collection). The table is not immediately deleted. I don't think you can force Azure to immediately delete it, but you could possibly raise a support ticket to ask them to delete it immediately. Have not tried this though.

Part of the reason is performance, I would assume, since a large delete could be hard on the overall system, and could slow Azure down for you + other customers. Also because some customers accidentally delete critical resources sometimes. (Or forgot to copy down any important config options from the resource before deleting it. I have some experience with that mistake.)

Encrypt it and lose the key is generally effective.

It is destroyed. But i believe there is a timeline where azure support can recover it for you until the deletion is final.

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