How does Qdrant store vectors and indexes on disk?

Qdrant supports storing vectors, HNSW graphs, and payloads either fully in RAM, fully on disk with memory mapping, or in hybrid configurations. Memory-mapped storage relies on the operating system page cache, which keeps frequently accessed data in memory while letting cold data live on SSD. Each collection can be configured independently, allowing hot tenants to stay in RAM while cold tenants move to disk. This flexibility lets a single Qdrant node serve billions of vectors with modest memory, trading some query latency for dramatic cost reduction.