Unable to create DiskANN vector index

Question

Hari 20

While attempting to create a DiskANN vector index in Azure Cosmos DB, the following error is returned:

{
  "ok": 0.0,
  "errmsg": "The diskann index is not enabled for this cluster tier",
  "code": 115,
  "codeName": "CommandNotSupported"
}

Even though the cluster is already running on M30 tier in the Switzerland North region.

Accepted answer

0 additional answers

Answer 1

Mahesh Kurva 6,850 Microsoft External Staff Moderator

Greetings!!

According to the latest official Azure documentation, DiskANN vector indexes are supported on M40 and above only, not M30.

The “Service Limits” page explicitly states:

“HNSW and DiskANN are available on M40 and above cluster tiers.” User's image

Please refer to the latest Azure Documentation link below:

Hope this helps. Do let us know if you any further queries.

If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.

Carlos Sosa 0 Reputation points

2025-08-07T21:01:50.76+00:00

But at this: https://learn.microsoft.com/en-us/azure/cosmos-db/mongodb/vcore/vector-search?tabs=diskann it states that it works M30 and up ? so ?
Mahesh Kurva 6,850 Reputation points Microsoft External Staff Moderator

2025-08-08T03:12:26.35+00:00

Hi Carlos Sosa

This is the latest official Azure documentation https://learn.microsoft.com/en-us/azure/cosmos-db/mongodb/vcore/limits?utm_source=chatgpt.com#vector-search-limits.Thank you.
Mahesh Kurva 6,850 Reputation points Microsoft External Staff Moderator

2025-08-08T03:13:07.7766667+00:00

Hi Hari,

Following up to see if the above answer was helpful. If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.