When it comes to MySQL and storage you will normally have to decide on 3 options: basic, general purpose v1 or v2.

Basic does support up to 1TB and is low-cost option but has no IOPs guarantee, not really recommended for production systems. General purpose v2 should be the one used because it uses latest storage infrastructure which can support up to 16-TB and 20000 IOPs a shown below.

Some key points on v2:

• Available is selected regions, please check: https://docs.microsoft.com/en-us/azure/mysql/concepts-pricing-tiers#general-purpose-storage-v2-supports-up-to-16-tb-storage
• General purpose storage v2 does not consume any memory from the compute node of MySQL.
• Backups on v2 are snapshot-based with no additional IO overhead.
• Anything created now within a supported region will be v2.

How can you check what you have? If you go to the pricing / scaling storage section of MySQL within Azure Portal you need to see what your maximum scale is. Below shows 4TB meaning my storage is version 1.

This is because I created my database in a region where v2 is not available at the time of writing (Norway East)

So always check the location of where you want to build your database server to get the best storage options and performance.