Azure – How does “Add Snapshot” work in the Azure Pricing Calculator

If you are looking for an good article I recommend

The Hows and Whys of SSDs by Robert Hallock

I linked to page 2, which contains the part which discusses clustering and block size.

[...] The solution to the problem is to increase the cluster size, for which there are several advantages:

• Reduced file system complexity; less clusters means less to organize.
• Increased read and write speed as cluster size approaches parity with block size.
• Decreased slack space if the system is primarily composed of large files.

Yet increased cluster size is not a magic bullet for solid state disks, as most people have a mix of information. Games often contain a myriad of small files and operating systems are the sum of small files almost as a rule; yet movies, music, archives and MMOs are perfect candidates for enlarged cluster sizes. More frustrating than the anchor of small clusters is the complicated process to get larger clusters under modern Windows operating systems. Such a feat requires premeditated use of programs like Acronis Disk Director which can increase cluster sizes prior to the installation of Windows. It is also possible to resize existing clusters, but such a procedure is accomplished with a frighteningly varied degree of success.

Thanks for getting back with that info. So, with AWS, you have some control. They are very much so far more "linux-centric" than Azure. With Azure, they give you what you get, and I believe that's it. We had looked into Azure ourselves and found some of the limitations therein.

Linux In The Cloud: Windows Azure vs. Amazon Web Services

That link above is about a year old, but I believe it still rings true. I have to say, I don't think you are alone with wanting to shrink the footprint of your Linux instances. 30GB is a joke for *NIX for sure.

So, if I'm not mistaken, I think AZURE Provisions as follows

*  /BOOT
*  /   (Temp Local Disk = SWAP + DATA)

Now, the caveat is that like most all IaaS platforms, thin provisioning is king. So that's where they will be getting you the savings I believe. While the full 30GB is provisioned, your BOOT volume is measured, and then whatever extra space you actually use, excluding PAGE BLOBS, or SWAP in the LINUX world. They call this "TEMPORARY LOCAL DISK" I think you should confirm with Azure, but you should be okay according to Azure from below:

Here's the official from Azure:

Do I need to purchase local disk storage with Virtual Machines separately?

All virtual machines in Azure are configured with at least two disks when you create the virtual machine – one is an operating system disk and the other is a temporary local disk, sometimes called a resource disk. Temporary Local disk storage is provided with Virtual Machines and is not charged separately. The operating system disk is charged at the regular rate for Disks. To explore virtual machines configurations visit here.

REFERENCE: Azure Linux VM Pricing & FAQ