ASRock Z87 Extreme11/ac LSI Mega RAID Storage Manager Guide - Page 177

raw capacity - A drive property indicating the actual full capacity of the drive before any coercion mode is applied to reduce the capacity. read policy - A controller attribute indicating the current Read Policy mode. In Always Read Ahead mode, the controller reads sequentially ahead of requested data and stores the additional data in cache memory, anticipating that the data will be needed soon. This speeds up reads for sequential data, but there is little improvement when accessing random data. In No Read Ahead mode, read ahead capability is disabled. In Adaptive Read Ahead mode, the controller begins using read ahead if the two most recent drive accesses occurred in sequential sectors. If the read requests are random, the controller reverts to No Read Ahead mode. rebuild - The regeneration of all data to a replacement drive in a redundant virtual drive after a drive failure. A drive rebuild normally occurs without interrupting normal operations on the affected virtual drive, though some degradation of performance of the drive subsystem can occur. rebuild rate - The percentage of central processing unit (CPU) resources devoted to rebuilding data onto a new drive after a drive in a storage configuration has failed. reclaim virtual drive - A method of undoing the configuration of a new virtual drive. If you highlight the virtual drive in the Configuration Wizard and click the Reclaim button, the individual drives are removed from the virtual drive configuration. reconstruction rate - The user-defined rate at which a reconstruction operation is carried out. redundancy - A property of a storage configuration that prevents data from being lost when one drive fails in the configuration. redundant configuration - A virtual drive that has redundant data on drives in the drive group that can be used to rebuild a failed drive. The redundant data can be parity data striped across multiple drives in a drive group, or it can be a complete mirrored copy of the data stored on a second drive. A redundant configuration protects the data in case a drive fails in the configuration. revertible hot spare - When you use the Replace Member procedure, after data is copied from a hot spare to a new drive, the hot spare reverts from a rebuild drive to its original hot spare status. revision level - A drive property that indicates the revision level of the drive's firmware. SAS - Acronym for Serial Attached SCSI. SAS is a serial, point-to-point, enterprise-level device interface that leverages the Small Computer System Interface (SCSI) protocol set. The SAS interface provides improved performance, simplified cabling, smaller connectors, lower pin count, and lower power requirements when compared to parallel SCSI. SATA - Acronym for Serial Advanced Technology Attachment. A physical storage interface standard. SATA is a serial link that provides point-to-point connections between devices. The thinner serial cables allow for better airflow within the system and permit smaller chassis designs. SCSI device type - A drive property indicating the type of the device, such as drive. serial no. - A controller property indicating the manufacturer-assigned serial number. strip size - The portion of a stripe that resides on a single drive in the drive group. stripe size - A virtual drive property indicating the length of the interleaved data segments that the RAID controller writes across multiple drives, not including parity drives. For example, consider DB09-000202-05 37857-02 Glossary Rev. F - May 2011 Copyright © 2011 by LSI Corporation. All rights reserved. Page 177