HP StorageWorks 2/16V ISS Technology Update Volume 8, Number 5 - Page 4

ISS Technology Update Volume 8, Number 5 drive. The iSCSI stack at both ends of the path is used to encapsulate SCSI block commands into Ethernet Packets for transmission over IP networks as illustrated in Figure 2-1. Figure 2-1. iSCSI is SCSI over TCP/IP File System Disk Driver SCSI SCSI MP** iSCSI initiator File System Disk Driver SCSI iSCSI MP** TCP/IP Ethernet iSCSI target iSCSI SCSI TCP/IP Ethernet Direct attached block storage using SCSI/SAS* * Serial Attached SCSI ** Multipathing EEtthheerrnneett Remote block storage using iSCSI Initiators include both software- and hardware-based initiators incorporated on host bus adapters (HBAs) and network interface cards (NICs). Software initiators require CPU resources to manage the iSCSI protocol stack. A more efficient approach is to offload the protocol management to a hardware-based iSCSI HBA or NIC. The operating system sees an iSCSI HBA or NIC as a SCSI device. Accelerated iSCSI Traditional software-based iSCSI initiators generate more processing overhead for the server CPU. By contrast, HP accelerated iSCSI offloads the protocol processing to an HP Multifunction Server Adapter so that CPU utilization is reduced and iSCSI performance is accelerated. HP Accelerated iSCSI supports all targets that are certified and supported by Microsoft iSCSI Software Initiator. ProLiant servers utilizing Accelerated iSCSI Multifunction server adapters show significant improvements in server efficiency over software-based iSCSI initiators. For more on the performance gains experienced with the Broadcom solution for HP hardwareassisted iSCSI Multifunction server adapters, read test results from the Tolly Group at http://www.tolly.com/TS/2008/HewlettPackard/iSCSISolutions/Tolly208305HPiSCSI.pdf. HP Accelerated iSCSI technical advantages There are several advantages derived from implementing Accelerated iSCSI: Standard configurations, including ideal input/output (I/O), read/write, random/sequential and queue sizes Improved I/O operations per second (IOPS) compared to iSCSI host bus adapters from other vendors Processing work offloaded to the NIC to free CPU cores for data-intensive workloads Increased server and IP storage application performance Increased iSCSI performance 4