Start with how the application accesses data.
Block storage presents a disk-like resource for an operating system or application. File storage exposes a filesystem interface for shared file access. Object storage uses an object and API model that can suit media, archives and application-generated files when the software supports it.
The interface matters as much as capacity. Identify required protocols, read and write patterns, concurrency and consistency expectations. An application designed for local file operations may need changes before it can use an object service effectively.
Model data movement and performance.
Provide current volume, expected growth, typical object or file size and the frequency of access. Describe ingest peaks, batch processing and where users or applications are located. For a large dataset, the time needed to transfer it can become part of the service requirement.
Compare capacity charges with requests, retrieval, network transfer and any minimum retention conditions. Include logs, replicas and versions in the estimate. Ask the proposal to state relevant performance and usage limits rather than assuming all stored data has the same cost profile.
Separate availability, history and recovery.
Define what happens after deletion, corruption, account compromise or a wider service incident. Replication, version history, retention controls and independent backups address different scenarios. Select the mechanisms around the events the business needs to recover from.
Set access permissions for applications, administrators and recovery operators. Include encryption and key ownership, with an agreed method of restoring access during an incident. Test retrieval and restoration of a representative dataset, including its metadata and application relationships.
Keep location and portability visible.
State location requirements for primary data, replicas, backups and operational access. Identify the chosen service and its applicable contractual terms. Where personal or sensitive information is involved, include the relevant organisational review before selecting the final data flow.
Plan an export format and estimate the effort and transfer cost of moving the data. Record who controls the account and can authorise deletion at the end of service. A complete quotation should explain storage, access, management and migration responsibilities together.