eDTU storage limit fast approaching limit

Question

Dear Experts,

I have an Elastic pool (200 eDTU) with the storage per pool set to 750 GB at the moment. There are 6 databases total in that pool. 5 of the databases are sized at 250 GB each and one is 500 GB.

My question is around the eDTU storage limit. For 200 eDTU , the max storage pool limit is 1 TB.

As the combined total storage of all the 6 databases is 1.75 TB, is this a correct allocation as I see two of the DBs are growing consistently and may not be able to accommodate in the Elastic pool with 200 eDTU. Could you please advise some recommendations.

Answer 1

Hi mo boy •,

Thanks for posting question in Microsoft Q&A forum.

In addition to Ronen's answer, for each elastic pool, you can optionally specify per database minimum and maximum DTUs to modify resource consumption patterns within the pool. Specified min and max values apply to all databases in the pool. Customizing min and max DTUs for individual databases in the pool is not supported.

You can also set maximum storage per database, for example to prevent a database from consuming all pool storage. This setting can be configured independently for each database.

Min and max per database DTU values apply to resource consumption by user workloads, but not to resource consumption by internal processes. For example, for a database with a per database max DTU set to half of the pool eDTU, user workload cannot consume more than one half of the buffer pool memory. However, this database can still take advantage of pages in the buffer pool that were loaded by internal processes.

Reference documentation: Database properties for pooled databases. Hope this helps. Let us know if you have further queries. Thank you.

Answer 2

Hi,

let me start from the end

Could you please advise some recommendations.

No. I cannot directly advice in such questions without fully learning the system, your needs and your limitations. The only things we can do is to answer specific questions or give general points (like golden rules).

As the combined total storage of all the 6 databases is 1.75 TB, is this a correct allocation

depend where the database are going

The basic idea of using elastic pool is the shared resources. You should think about the databases as one pool and not as separate entities.

If one database growth while the other one shrinked at the same size, then in total size is the same.

You should not plan a system, which might need in total more thzn you provide it!

This is the main point to think about, and according to your description I am getting the feeling that you think your database will need more resources than you provide it.

On the other side of the equation, the main advantage of using cloud is the flexibility in resources. If your resources fit your current needs and you can monitor it and change the resources BEFORE it will be needed, then your best solution might be to use less resources until needed more.

last point and this time: You must remember that the eDTU is more than just storage size!

In many cases, I will recommend my client to sue higher tier to get more CPU/Memory even if the storage fits his needs and vise versa. The difficult using price tier based on DTU/eDTU is that you get an combine of all resources and no control on specific resource.