Scott B Clark, Age 6061 Lake Farm Rd, Port Angeles, WA 98362

6295591, Sep 25, 2001

Mar 30, 1999

9/281084

Richard Bealkowski - Redmond WA
Scott Douglas Clark - Rochester MN
Sudhir Dhawan - Austin TX
Robert Allen Drehmel - Goodhue MN

International Business Machines Corporation - Armonk NY

G06F 1200
G06F 1300
H05K 1000
H02K 305

711165

A method of providing maintenance for a memory device of a computer system without interrupting operation of the computer system, by partially mirroring a primary memory array in a secondary memory array, wherein the secondary memory array has a different amount of available memory than the primary memory array. Values are copied from the primary memory array to the permanent storage device, allowing the primary memory array to quiesce and be serviced while using the secondary memory array to operate the computer system. Thereafter, the primary memory array is brought on-line, and the mirrored values are written back from the secondary memory array to the primary memory array. The memory service program itself may be embedded in the operating system. In an illustrative embodiment, the primary memory array is located on a first removable memory card, and the secondary memory array is located on a second removable memory card. The amount of memory available in the secondary memory array may be programmable.