A drive bay is not a storage architecture.

Describe every drive position

Create a position-based schedule before requesting storage: front, middle, rear and internal boot. Put the required media type and capacity against each position. A front-view photograph helps identify the physical layout but does not prove the electrical path or controller topology.

The SR650 V4 documentation distinguishes AnyBay positions from NVMe-only positions; these are not interchangeable terms. The R7725 also has multiple alternative chassis layouts. Quote the chosen arrangement, not a collection of maximum bay counts from different arrangements.

Keep media and control separate

Request the controller or HBA PN, firmware, backplane identity and cable set, along with the boot arrangement. Ask which drives are visible to which controller and where any RAID function runs. A diagram is often clearer than a sentence such as “NVMe RAID supported”.

The SYS-222C-TN product page explicitly identifies a VROC hardware-key requirement for its listed NVMe RAID path. Put that option into the quoted scope when it is required. Samsung PM1653 is a SAS family, so it must not be described as a PCIe NVMe alternative just because the enclosure looks similar.

Define usable capacity and replacement policy

Write usable-capacity expectations and the proposed RAID or storage-software layout separately from raw drive capacity. Include spare policy, boot separation and whether the application has its own resilience mechanism. Treat sizing calculations as a proposal until the software and controller constraints have been checked.

For replacement drives, request full identifiers, firmware, carrier requirements and the target array or server model. Ask for compatibility evidence and a written substitution policy. A matching capacity and interface alone is not enough information to approve an array replacement.

Original procurement guidance. Engineering considerations are not a manufacturer-validated configuration or a performance guarantee.

Documentation used for this guide.