HP ProLiant 4000 SMART-2DH Array Controller Reference Guide - Page 17

1-6 Features NOTE: The SMART-2DH Controller Array Accelerator is equipped with a switch that may be activated to fine tune system performance. See Appendix E for further information. The Array Accelerator is made of ECC (Error Checking and Correcting) memory, providing a high level of data integrity. ECC memory detects and corrects hard and soft memory errors without affecting performance. The Array Accelerator is backed up with onboard rechargeable batteries, ensuring that the data temporarily held (cached) there is safe even with equipment failure or power outage. This is particularly important for data that has been cached by a posted-write, but has not yet been written to the hard drives. The batteries preserve data in the Array Accelerator for up to four days. IMPORTANT: The rechargeable batteries on a new SMART-2DH Array Controller may be discharged when the board is first installed. During server power up with discharged Array Accelerator batteries, Power-On Self-Test (POST) displays the code "1794," indicating that the Array Accelerator is disabled. This is not a problem that requires action on your part. The Array Accelerator is automatically enabled when the batteries are charged to 90% of their capacity. It may take up to 36 hours for the internal circuitry to charge the batteries fully. During this time, the Array Accelerator will be disabled, but the SMART-2DH Array Controller will function properly, although without the performance advantage of the Array Accelerator. The Array Accelerator, with backup batteries, is located on a removable daughter board. In the unlikely event of failure, the Array Accelerator can be detached from the failed SMART-2DH Array Controller and attached to a replacement SMART-2DH Array Controller. If the configuration information stored in the Array Accelerator matches that stored on the drives, any valid posted-write data being held in the cache is automatically written to the drives attached to the replacement Array controller. Thus, data being held in the Array Accelerator memory can be recovered despite failure of the main SMART-2DH Array Controller board. Writer: Pamela King Project: SMART-2DH Array Controller Reference Guide Comments: 295469-002 File Name: B-CH01.DOC Last Saved On: 2/27/98 11:23 AM COMPAQ CONFIDENTIAL - NEED TO KNOW REQUIRED