SCSI Trade Association
October 2009
Q1. What is the Advanced Connectivity Roadmap?
A1. The Advanced Connectivity roadmap is the STA connectivity roadmap to guide the industry through future SAS storage solutions. It specifies the Mini-SAS High Density (HD) (SFF- 8643/8644) connector as the converged connectivity scheme for SAS-based deployments. In addition, it defines SAS Connectivity Management for simplifying cable and connectivity management.
Q2. Name the factors that stimulated provision of the Advanced SAS Connectivity Roadmap.
A2. Factors which drove development and provision of the Advanced SAS Connectivity Roadmap include simplification of cable and connector options and the provision of managed connectivity standards. Additional factors include providing high-density connectivity and the extension of active copper cable to 20m and optical cable to 100m.
Q3. What is a Mini-SAS High Density (HD) connector and how does it improve connectivity?
A3. The Mini-SAS HD connector doubles the port density over the Mini-SAS connector. Both internal and external solutions are available and it is electrically improved with less cross-talk and a much better signal-to-noise ratio. It supports active copper and optical cabling as well as SAS Connectivity Management.
Q4. What advantages does the extension of copper cables to 20m or optical cables to 100m provide to SAS storage systems?
A4. Longer cables enable more box-to-box, server-to-storage and rack-to-rack connections, thereby providing greater scalability (permitting accommodation of more spindles). Longer cables also allow greater configuration deployment flexibility.
Q5. In which external storage applications is 6Gb/s SAS now advancing dramatically?
A5. Currently, 6Gb/s SAS has made significant advances in drive-attach and there is a growing opportunity for host-attached applications as well.
Q6. Will Advanced SAS Connectivity extend beyond 6Gb/s SAS?
A6. Yes, it will be extended to 12Gb/s SAS when this next SAS generation enters the market.
Q7. What is SAS Connectivity Management?
A7. SAS Connectivity Management is a consistent way of managing the cabling plan in any SAS system using the Mini-SAS HD connector. It is capable of detecting the presence or absence of a cable, number of SAS ports within the connector, what type of connection is being supported, (active, passive, optical), and other attributes important to storage system usability and serviceability.
Q8. What can Advanced SAS Connectivity contribute to cloud computing, large data centers and massive data enterprises?
A8. Advanced SAS Connectivity provides greater distance, flexibility, scalability, serviceability and usability to large-size storage installations and uses.
Q9. What are the primary advantages of SAS Connectivity Management?
A9. SAS Connectivity Management defines connectivity support including connection discovery and cable management; improved serviceability and usability without the need for mechanical keys; it also provides rapid fault isolation and minimal configuration errors; and last, it lowers Total Cost of Ownership (TCO).
Q10. In which SAS generation will SAS Connectivity Management appear?
A10. SAS Connectivity Management may be implemented rather quickly on the existing 6Gb/s SAS generation supported by the Quad Small-factor Pluggable (QSFP) connector. While STA recognizes that some homogeneous deployments may use this connector, it is not the preferred connector for heterogeneous deployments. Mini-SAS HD systems are expected to take advantage of SAS Connectivity Management. These advantages will appear in the current 6Gb/s SAS generation, possibly in the first half of 2010. They will appear subsequently in the 12Gb/s SAS generation.
