每台存储服务器上的磁盘控制器都定期对控制器电池进行放电和充电。操作期间，写高速缓存策略从回写高速缓存更改为直写式高速缓存。直写式高速缓存模式比回写高速缓存模式慢。不过，在存储服务器断电或出现故障时，回写高速缓存模式存在丢失数据的风险。对于早于发行版 11.2.1.3 的存储服务器发行版，此操作每月执行一次。对于 Oracle Exadata Storage Server Software 发行版 11.2.1.3 和更高版本，此操作每三个月执行一次，例如，在一月、四月、七月和十月的 17 日 01:00 执行。
CellCLI> ALTER CELL bbuLearnCycleTime="2011-01-22T02:00:00-08:00"
在周期结束后，时间将恢复为默认记忆周期时间。
CellCLI> LIST CELL ATTRIBUTES bbuLearnCycleTime
存储服务器为单元上的逻辑驱动器生成有关高速缓存模式的状态的提示性警报，例如：
HDD disk controller battery on disk controller at adapter 0 is going into a learn cycle. This is a normal maintenance activity that occurs quarterly and runs for approximately 1 to 12 hours. The disk controller cache might go into WriteThrough caching mode during the learn cycle. Disk write throughput might be temporarily lower during this time. The message is informational only, no action is required.
# /opt/MegaRAID/MegaCli/MegaCli64 -AdpBbuCmd -GetBbuStatus -a0
输出示例。
BBU status for Adapter: 0 BatteryType: iBBU08 Voltage: 3721 mV Current: 541 mA Temperature: 43 C BBU Firmware Status: Charging Status : Charging Voltage : OK Temperature : OK Learn Cycle Requested : No Learn Cycle Active : No Learn Cycle Status : OK Learn Cycle Timeout : No I2c Errors Detected : No Battery Pack Missing : No Battery Replacement required : No Remaining Capacity Low : Yes Periodic Learn Required : No Transparent Learn : No Battery state: GasGuageStatus: Fully Discharged : No Fully Charged : No Discharging : No Initialized : No Remaining Time Alarm : Yes Remaining Capacity Alarm: No Discharge Terminated : No Over Temperature : No Charging Terminated : No Over Charged : No Relative State of Charge: 7 % Charger System State: 1 Charger System Ctrl: 0 Charging current: 541 mA Absolute State of Charge: 0% Max Error: 0 % Exit Code: 0x00