You can build a high availability Vault cluster with any storage backend.

Not all Vault storage backends provide the necessary primitives, such as leader election and consistent storage for HA locking, which are crucial for building a resilient, highly available Vault cluster.

Vault's high availability (HA) mode requires specific storage backends that support distributed consensus and leader election, such as Consul, Integrated Storage (Raft), or certain cloud provider storage solutions. Many simpler storage backends, like a file system or some databases, lack the necessary locking and coordination primitives to enable HA.