Way back in May, the Azure team published a bunch of new images based on a 30GB boot disk, instead of the standard 127 GB disk. Why? To save YOU money. In many cases, it’s optimal to run applications from a second disk – SQL data, according to best practice, should run across three (system, data, log) or more drives; IIS can be configured to serve data and log to a secondary disk, and AD data must be stored on a secondary disk that has caching disabled. Using a dedicated set of data disks, separate from the OS, can provide performance and reliability improvements.
By using a second disk to run applications, it’s likely that you only need 32-64GB of space on the OS Disk. If you use the smaller image size, you can use a small S1 disk instead of the S2 128GB disk.
Look at this example, using a premium disk – the price jumps from $5.84 to $21.79 per disk! (West US2, Canadian Dollars)
Standard disk savings are similar, with a jump in cost from $1.87 to $7.16!
To use these disks, look for images that are prepended with “[smalldisk]” in the image title on Azure Portal. For Powershell, CLI and ARM Templates (which is where you’re doing all your work, right?) the image SKU is appended with “-smalldisk”.