Tuesday, November 2, 2021

Azure SQL Managed Instance Business Critical16TB scale is coming soon in limited public preview

Storage limit of 16TB is coming soon in limited public preview for SQL Managed Instance (SQL MI) Business Critical (BC) tier, along with increased storage to vCore ratios.

Note: A few months ago, we launched a preview for SQL MI General Purpose (GP) 16 TB. From today, the 16 TB storage is in general availability for SQL MI GP!


What is new?

SQL Managed Instance Business Critical 16 TB scale: For many database workloads with significant data volume, but utmost storage latency and availability requirements, the previous limit for SQL MI BC storage size of 4 TB has been a challenge. We are happy to announce that the storage limit for BC is quadrupled and you can create or upgrade your BC Instances to host up to 16 TB of data.

Increased storage to vCore ratios: You might ask what about other prerequisites; for example, to use 2 TB of storage, one must have had a BC instance with at least 24 vCores. Do not worry, we also improved storage to vCore ratios on the way to 16 TB. Now, to use 2 TB of storage, one must have a BC instance with only 16 vCores. This will save you 8 vCores expense or, if you have a failover group, this means 16 vCores of saving! Check out the “Are there any requirements?” section below for the full list of the new storage to vCore ratios. 


What is a limited public preview and how can I sign up for it?

In this sense, limited preview stands for the public preview that is available in a limited number of regions. In these regions, SQL MI BC 16 TB is in public preview meaning that there is no need to sign up.


What regions are supported?

To be eligible for 16 TB of storage, SQL MI Business Critical instance must be in one of the regions that the preview is available. The list of the supported regions will change as we roll out this improvement incrementally across the globe and you can check on the latest status here.


Are there any requirements?

Yes. To be able to choose a specific combination of storage size and vCore count, your SQL MI BC instance must be running on a particular hardware generation. For instance, to have 16 TB of storage in SQL MI BC, you need to configure the compute as: Premium series – memory optimized hardware generation and 64 vCores. See Figure 1.


Figure 1 - Azure Portal experience when configuring Compute + Storage


To understand this requirement better, we should introduce our new hardware generations first.


New hardware generations

The new premium-series hardware is based on Intel® Ice Lake processors which provide better compute and memory performance as well as improved IO and network experience over the standard-series (Gen5) hardware offering. A new memory optimized option within the premium-series provides even more memory per vCore and is thereby optimal for the most memory-intensive workloads. See Table 1.

Hardware Generation


Max memory per vCore

Standard Series (Gen5)

Intel® Broadwell , Intel® Skylake, Intel® Cascade Lake

5.1 GB RAM/vCore

Premium Series

Intel® Ice Lake

7 GB RAM/vCore

Premium Series – Memory Optimized

Intel® Ice Lake

13.6 GB RAM/vCore

Table 1 - Key characteristics for  new SQL MI hardware generations


For more details on the new hardware generations and their characteristics, see the Announcing the new premium-series hardware for SQL Managed Instance blog.


Increased storage to vCore ratios - more memory for less vCores!

Previously, the maximum storage size for SQL MI BC was 4 TB, which was available for every BC instance that had at least 32 vCores (Table 2, column SQL MI BC - BEFORE). Now, with BC 16 TB in preview, this experience changes according to the mapping shown in Table 2, column SQL MI BC – NOW.



SQL MI BC – NOW (new in orange)

Max instance storage size (reserved)

Gen4: 1 TB
- 1 TB for 4, 8, 16 vCores
- 2 TB for 24 vCores
- 4 TB for 32, 40, 64, 80 vCores

Standard-Series (Gen5)
- 1 TB for 4, 8, 16 vCores
- 2 TB for 24 vCores
- 4 TB for 32, 40, 64, 80 vCores

- 1 TB for 4, 8 vCores
- 2 TB for 16, 24 vCores
- 4 TB for 32 vCores

- 5.5 TB for 40, 64, 80 vCores
Premium-Series - Memory Optimized:

- 1 TB for 4, 8 vCores
- 2 TB for 16, 24 vCores
- 4 TB for 32 vCores

- 5.5 TB for 40 vCores

- 16 TB for 64 vCores

Table 2 - Storage to vCore ratios in SQL MI BC 


For more details on other limitations, see SQL Managed Instance resource limits.



In this article, we discussed the latest scale and performance improvements in SQL Managed Instance Business Critical: SQL Managed Instance Business Critical with 16 TB storage and more favorable storage size limits per vCore count. Thank you for reading and enjoy using SQL Managed Instance with increased storage capacity and much better performance.

Posted at https://sl.advdat.com/3CGhJ6C