Dell H310 User Manual

Contents

Dell H310 User Manual Manual pdf 23 page image

Controller Cache PreservationThe controller is capable of preserving its cache in the event of a system power outage or improper system shutdown.The PERC H710, H710P, and H810 controllers are attached to a Battery Backup Unit (BBU) that provides backup powerduring system power loss to preserve the controller's cache data.Cache Preservation With Non-Volatile Cache (NVC)In essence, the NVC module allows controller cache data to be stored indefinitely. If the controller has data in the cachememory during a power outage or improper system shutdown, a small amount of power from the battery is used totransfer cache data to a non-volatile flash storage where it remains until power is restored and the system is booted.Recovering Cache DataThe dirty cache LED that is located on the H710 and H810 cards can be used to determine if cache data is beingpreserved.If a system power loss or improper system shutdown has occurred:1. Restore the system power.2. Boot the system.3. To enter the BIOS Configuration Utility, select Managed Preserved Cache in the controller menu.If there are no virtual disks listed, all preserved cache data has been written to disk successfully.Battery Transparent Learn CycleNOTE: Batteries are only supported on PERC H710, H710P, and H810 cards.A transparent learn cycle is a periodic operation that calculates the charge that is remaining in the battery to ensurethere is sufficient energy. The operation runs automatically, and causes no impact to the system or controllerperformance.The controller automatically performs the Transparent Learn Cycle (TLC) on the battery to calibrate and gauge its chargecapacity once every 90 days. The operation can be performed manually, if required.NOTE: Virtual disks stay in Write Back mode, if enabled, during transparent learn cycle. When the TLC completes,the controller sets the next TLC to +90 days.TLC Time FrameThe time frame for completion of a learn cycle is a function of the battery charge capacity and the discharge and chargecurrents used. For PERC H710 or H810 cards, the expected time frame for completion of a learn cycle is approximatelyseven hours.Conditions For Replacing The BatteryThe PERC battery is marked Failed when the state or health of the battery is declared bad. If battery is declared failedthen the firmware runs learn cycles in subsequent reboots until the battery is replaced. The virtual disk then transitionsto Write Back mode.23