Windows Azure OS Disk

Question

Need clarification on the way storage is accounted for on Azure. The short version of the question is whether an OS Disk created for a Virtual Machine is charged towards the storage account.

The long version: I'm current experimenting with the VS studio ultimate subscription: https://www.windowsazure.com/en-us/offers/ms-azr-0012p, which allows up to 2 small instances and 45 GB of storage. But when a small instance is created, it automatically creates a 30GB OS Disk, which mean I cannot possibly create two small instances (not simultaneously) without paying for it? Is this how Azure works or the 45GB of storage actually refers to Data Disks.

Answer 1

I believe you get charged on the usage of your disks. For example, I could create a small VM and attach a couple of 1TB disks to it and not get charged much at all unless I start filling those 1TB disk with data.

It sounds like you've got a 45GB quota but you could create your two 30GB VMs just fine although there won't be a lot of room for data afterwards.

Answer 2

Azure Cloud Services automatically come with a set of: CPU. Memory, Storage and bandwidth throttling...

http://msdn.microsoft.com/en-us/library/windowsazure/ee814754.aspx

You won't get charged if you create 2 small VMs...that is about 1,500 compute hours and will be covered by your subscription.

If you deploy a VM Role (instead of the PaaS web worker) and attach a stripped drive, then yes you will be charged for the storage/transactions. All Azure OS drives are tied to blob storage, so its easy to determine the costs.

BTW...set it up and have it up for a day and you can see in the billing statement to see the charges. Azure has some nuances that you need to consider when pricing costs...for example, just having storage running or a worker in an empty loop counts as transactions. The price is so low for them that it usually doesn't matter...but there are ways to mitigate costs even further.