HP Surestore Disk Array FC60 HP SureStore E Disk Array 12H User's and Service - Page 268

Glossary Glossary Reload Relocated Blocks Restart SCSI SCSI HBA SCSI ID SDTR Traditionally, RAID systems required the entire user data set to be rewritten in order to add more capacity or adjust the RAID mode. The disk array does not require a Reload to make use of additional disk space because of the automatic Balancing and Dynamic Data Migration inherent in HP AutoRAID™ Array Technology. Relocated Blocks are data blocks that are relocated from RAID 0/1 to RAID 5 (or vice versa) when performing a write. The process of bringing the array back on line. Typically done following a Shutdown, a restart copies vital configuration information from the disks to NVRAM on the array controller. SCSI stands for "Small Computer System Interface." This is an industry-standard interface that defines the mechanical, electrical, and functional requirements for connections and communication between small computers and disk drives and other peripherals. The SCSI ID (identification or address) uniquely identifies the device on the SCSI channel. The SCSI HBA (Host Bus Adapter) is the card installed in the server that provides the connection for the disk array. The SCSI HBA manages the transfer of data between the server and the disk array. Multiple SCSI devices can be connected to each HBA. The SCSI ID is a unique number assigned to each device connected to a SCSI bus. This number is used by the HBA to address each device on the bus. Each controller in the disk array is assigned its own SCSI ID. SDTR stands for "Synchronous Data Transfer Request." SDTR controls the data rate on the SCSI bus used by the host and the array. SDTR also determines the negotiation protocol of the host. If SDTR is enabled, the array will initiate negotiation protocol; if disabled, the host will initiate negotiation protocol. In either case, the disk array will always respond to any requests made by the host. 268