Recommendations For Storage On Azure SQL DB Managed Instances

Dimitri Furman has some thoughts on database storage architecture for Azure SQL Database Managed Instances:

MI GP uses Azure Premium Storage to store database files for all databases, except for the tempdb database. From the perspective of the database engine, this storage type is remote, i.e. it is accessed over the network, using Azure network infrastructure. To use Azure Premium Storage, MI GP takes advantage of SQL Server native capability to use database files directly in Azure Blob Storage. This means that there is not a disk or a network share that hosts database files; instead, file path is an HTTPS URL, and each database file is a page blob in Azure Blob Storage.

Since Azure Premium Storage is used, its performance characteristics, limits, and scalability goals fully apply to MI GP. The High-performance Premium Storage and managed disks for VMs documentation article includes a section describing Premium Storage disk limits. While the topic is written in the context of VMs and Azure disks, which is the most common usage scenario for Azure Premium Storage, the documented limits are also applicable to blobs. As shown in the limits table in the documentation, the size of the blob determines the maximum IOPS and throughput that can be achieved against the blob. For MI GP, this means that the size of a database file determines the maximum IOPS and throughput that is achievable against the file.

The disk/blob size shown in the limits table is the maximum size for which the corresponding limit applies. For example, a blob that is > 64 GB and <= 128 GB (equivalent to a P10 disk) can achieve up to 500 IOPS and up to 100 MB/second throughput.

Read the whole thing if you’re looking at Managed Instances, but there are some tips for SQL Server in Azure IaaS.

Related Posts

What To Watch When Using VSS Snapshots

Erik Darling shows us the wait stats associated with the Volume Shadow Copy Service (VSS): A while back I wrote about the Perils of VSS Snaps. After working with several more clients having similar issues, I decided it was time to look at things again. This time, I wanted blood. I wanted to simulate a slow […]

Read More

Azure SQL Database SLAs

Arun Sirpal ponders the Azure SQL Database service level agreement: Lets just get straight to the point, Azure SQL Database across all service tiers gives you the customer a SLA of 99.99% up-time. This means potential unavailability periods shown below. Good, bad, you decide. The point is that even in the cloud we “could” potentially encounter downtime. […]

Read More

Categories

July 2018
MTWTFSS
« Jun Aug »
 1
2345678
9101112131415
16171819202122
23242526272829
3031