Impact of Increasing Storage and Cores for Azure SQL Database in Business Critical Tier

Question

Hi Team,

What is the impact of maximum storage size for Azure SQL Database within the Business Critical service tier. we are currently using a Business Critical configuration with 8 cores and 2TB of storage, and plan to increase it to 12 cores and 2.5TB due to data capacity requirements.   

1. The impact of expanding the virtual cores, including the processing time and any other concerns.   
2. The impact of expanding the disk, including the processing time and any other concerns

PS - Based on common issues that we have seen from customers and other sources, we are posting these questions to help the Azure community.

Answer 1

Greetings!

There will be a small downtime would be expected during scaling operation, When you expand the vcore on sql database, it will have small downtime usually several seconds to 1 min. expected processing time is at longest 1 min/ 1 GB for Business critical, but probably it will not take that long (1 min / 1 GB is just longest scenario as noted in doc). it will have small downtime and drop any connections during downtime
When you expand only disk size on sql database, there is no downtime expected if it is within the same service level (within BC or within GP, because there is no disk change, just expand), however we can not guarantee that there is no downtime (technically it will no downtime), so I would say, mostly there is no downtime.

Scale single database resources - Azure SQL Database | Microsoft Learn

expected time latency till complete scaling with below docs.

https://learn.microsoft.com/en-us/azure/azure-sql/database/single-database-scale?view=azuresql&tabs=azure-portal#latency

Regards

Geetha