HP DL360 Serial Attached SCSI storage technology, 2nd Edition - Page 8

SAS/SATA interoperability Using the SAS interface, SAS drives, SATA drives, or a mix of both SAS and SATA drives will function in the same storage enclosure. With this broad range of storage solutions (Figure 4), IT managers can choose storage devices based on reliability, performance, and cost. Because the SAS architecture features a proven SCSI command set, advanced command queuing, and advanced verification/error correction, SAS is the ideal solution for mission-critical enterprise storage applications. SAS supports three protocols to handle communications with various devices: Serial Management Protocol (SMP) - manages the point-to-point topology of expanders and enclosures Serial SCSI Protocol (SSP) - facilitates communication with SAS devices and existing SCSI software SATA Tunneling Protocol (STP) - allows SAS controllers to communicate with SATA devices through expanders Figure 4. The SAS architecture provides flexible solutions ranging from entry level NAS in desktop environments to mission-critical RAID systems that complement Fibre Channel technology. 8