Compaq 3200 - Manual (Page 157)

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Compaq Smart Array 3200 Controller Reference Guide
Writer: Rickard Project: Compaq Smart Array 3200 Controller Reference Guide Comments: 340862-002
File Name: L-APPE.DOC Last Saved On: 12/7/98 9:30 AM
COMPAQ CONFIDENTIAL - NEED TO KNOW REQUIRED
Data Protection
The Array Accelerator was designed to protect data integrity. Batteries and ECC
memory protect the cache memory. This allows end users to take full advantage
of the performance without sacrificing reliability.
The Array Accelerator is also removable. This, along with its integrated
batteries, means the Array Accelerator can be removed from one Smart Array
3200 Controller and installed on another. If there is any data in the Array
Accelerator that has not been written to the hard drive, it can be transferred to
another Smart Array 3200 Controller. This might happen if the Smart Array
3200 Controller or server failed before the cached data could be stored on a
drive.
ECC Memory
To assure further data integrity, the Array Accelerator cache is made up of Error
Checking and Correcting (ECC) memory. ECC memory detects and corrects all
single-bit memory errors in multiple DRAMs. It also detects all two-bit memory
errors in any position and most three- and four-bit memory errors in a single
DRAM. An entire DRAM can also fail without data loss. This ensures the
correction of common memory errors without interrupting system operation.