What is the maximum number of "allowed" secrets in a standard open-source installation of Vault?

The correct answer highlights that there is no specific limit to the maximum number of "allowed" secrets in a standard open-source installation of Vault. This is fundamentally tied to the design and capabilities of the backend storage system being utilized to store those secrets.

HashiCorp Vault is designed to be highly scalable and flexible. It can work with various backend storage solutions, such as Consul, Amazon S3, or even a local file system. The actual number of secrets that can be stored relies heavily on the capacity and performance characteristics of these backends. For example, some backends may have practical limitations based on available disk space, while others might handle much larger datasets without issues.

This architecture allows users to scale Vault according to their needs rather than imposing arbitrary limits within the application itself. Therefore, as long as the backend is capable of supporting the volume, you can store a virtually unlimited number of secrets.