ASRock Z87 Extreme11/ac LSI Mega RAID Storage Manager Guide - Page 173

consistency check rate - The rate at which consistency check operations are run on a computer system. controller - A chip that controls the transfer of data between the microprocessor and memory or between the microprocessor and a peripheral device such as a drive. RAID controllers perform RAID functions such as striping and mirroring to provide data protection. MegaRAID Storage Manager software runs on LSI SAS controllers. copyback - The procedure used to copy data from a source drive of a virtual drive to a destination drive that is not a part of the virtual drive. The copyback operation is often used to create or restore a specific physical configuration for a drive group (for example, a specific arrangement of drive group members on the device I/O buses). The copyback operation can be run automatically or manually. Typically, a drive fails or is expected to fail, and the data is rebuilt on a hot spare. The failed drive is replaced with a new drive. Then the data is copied from the hot spare to the new drive, and the hot spare reverts from a rebuild drive to its original hot spare status. The copyback operation runs as a background activity, and the virtual drive is still available online to the host. current write policy - A virtual drive property that indicates whether the virtual drive currently supports Write Back mode or Write Through mode. • In Write Back mode the controller sends a data transfer completion signal to the host when the controller cache has received all of the data in a transaction. • In Write Through mode the controller sends a data transfer completion signal to the host when the drive subsystem has received all of the data in a transaction. default write policy - A virtual drive property indicating whether the default write policy is Write Through or Write Back. In Write Back mode the controller sends a data transfer completion signal to the host when the controller cache has received all of the data in a transaction. In Write Through mode the controller sends a data transfer completion signal to the host when the drive subsystem has received all of the data in a transaction. device ID - A controller or drive property indicating the manufacturer-assigned device ID. device port count - A controller property indicating the number of ports on the controller. drive cache policy - A virtual drive property indicating whether the virtual drive cache is enabled, disabled, or unchanged from its previous setting. drive group - A group of drives attached to a RAID controller on which one or more virtual drives can be created. All virtual drives in the drive group use all of the drives in the drive group. drive state - A drive property indicating the status of the drive. A drive can be in one of the following states: • Unconfigured Good: A drive accessible to the RAID controller but not configured as a part of a virtual drive or as a hot spare. • Hot Spare: A drive that is configured as a hot spare. • Online: A drive that can be accessed by the RAID controller and will be part of the virtual drive. • Rebuild: A drive to which data is being written to restore full redundancy for a virtual drive. • Failed: A drive that was originally configured as Online or Hot Spare, but on which the firmware detects an unrecoverable error. DB09-000202-05 37857-02 Glossary Rev. F - May 2011 Copyright © 2011 by LSI Corporation. All rights reserved. Page 173