At the end of 2021, I started using the new SFTP preview feature on Azure Data Lake Storage Gen 2. It was a great new addition to the storage account to help get data to our data lake for projects.
Originally there was no charge related to it or indication of future cost inside the Azure storage account settings when enabled. SFTP officially became GA in October 2022, and Microsoft planned to start charging for it in December 2022. When I created a new storage account and enabled SFTP in December 2022, there was no indication of an additional charge, and from December 2022 to April 2023, there was no change in my monthly charges.
Suddenly on the April bill was a charge of $95.09 for that storage account, which I had yet to use. I reached out to Azure Support and received a refund. I figured it was a billing mistake and didn't think about it again until the other day when I received a bill for more than double last month’s bill ($223.20) for the same unused storage account!
Immediately I created a ticket with Azure Support and inquired why there was a sudden uptick in cost when the storage account was not even used.
It turns out that there was a billing bug that wasn't discovered or fixed until mid-April 2023. Microsoft then fixed the bug and started to charge everyone who implemented SFTP on their storage accounts.
The cost was originally $0.30 a day. In my case, it was not charging that against this storage account since December 2022, when I created the storage account with the SFTP feature enabled. Once they fixed the billing bug in the middle of April, suddenly, the account was being charged $0.30 an hour!
I received no notification when I logged in to the Azure portal, nor an email stating charges were being increased, and there was no explanation on the bill as to why my charges increased. I'm not sure why this wasn't communicated previously. Azure Support said that Microsoft had released/sent an official email statement notifying customers of the increase in pricing and refunding customers for the period before the bug was known/realized.
As of now, at least they have added a notification when you go to enable SFTP, stating there are hourly charges and a link to review them.
If you need to use an SFTP site but don't want to have the additional cost of having it on constantly, there is a solution. Use a command to enable and disable the SFTP option on your storage account before and after you use it.
Microsoft has confirmed that the charges can be stopped and started using the following commands or an API in this Q&A post.
To enable/start SFTP on your storage account, use this command:
az storage account update --name mysftp --resource-group mysftp-rg
--enable-sftp falseTo disable/stop SFTP on your storage account, use this command:
az storage account update --name mysftp --resource-group mysftp-rg
--enable-sftp falseIf you want to use the API, Michael Stephenson has a detailed blog post on automating the enabling and disabling the SFTP option using a Logic App.