Azure web app - D:\local storage has hit storage limit

Question

I have a web app hosted on Azure that is throwing errors when I try to deploy from Devops pipeline.
I've traced the error to the d:\local directory of the web app which shows as full in the web app KUDU environment

D:\home usage: 256,000 MB total; 251,790 MB free
d:\local usage: 21,504 MB total; 0 MB free

I'm not able to open a KUDU console or powershell, because it gives a disk space error:

Parser Error Message: There is not enough space on the disk.

In Azure quotas, the Storage plan quota for our service level is 250 Gib, app usage is 4.11 GiB

My current understanding from:
https://github.com/projectkudu/kudu/wiki/Understanding-the-Azure-App-Service-file-system
is that d:\local has a lower limit, looks like we;ve hit the 21 gigs.

Question: How do I find out which storage account in azure is holding this D:\ drive, and how can I go in and clean it out other than the KUDU console?

There is also some troubleshooting in the App code itself to see where it is using the D:\Temp folder and if it is deleting temp files, I suspect not, but I can't do this until I can push code back up to the server again!

Answer 1

Thanks for asking question! You may want to know that App Service is a service running on top of the Azure PaaS (platform as a service) infrastructure. As a result, the local drives that are "attached" to a virtual machine are the same drive types available to any worker role running in Azure. This includes:

• An operating system drive (the D:\ drive)
• An application drive that contains Azure Package cspkg files used exclusively by App Service (and inaccessible to customers)
• A "user" drive (the C:\ drive), whose size varies depending on the size of the VM.

So, Its important to monitor your disk utilization as your application grows. If the disk quota is reached, it can have adverse effects to your application. For example:

• The app may throw an error indicating not enough space on the disk.
• You may see disk errors when browsing to the Kudu console.
• Deployment from Azure DevOps or Visual Studio may fail with ERROR_NOT_ENOUGH_DISK_SPACE: Web deployment task failed.
(Web Deploy detected insufficient space on disk).
• Your app may suffer slow performance.

Also, its little tricky to figure out this issue as you may have multiple Web Apps in an App Service Plan. If one of the Web Apps is taking more disk space than the others, you may not be able to easily identify which Web App to investigate.

You may use Quotas blade at the Web App level from Azure portal might be helpful.

Please check below articles on this:
Azure App Service - What is taking my disk space for my Azure Web App ?

Review and manage your web site disk space in Azure

In case issue persists request you to send an email to AzCommunity[at]Microsoft[dot]com referencing this thread, we would like to work closer with you on this matter.

Disclaimer: This response contains a reference to a third-party World Wide Web site. Microsoft is providing this information as a convenience to you.

Answer 2

Hello, I am also curious to find out the OPs question regarding how to determine the files that are responsible for filling up storage. This was not answered. Kind regards