Method and system for repairing memory failure in a computer system in one aspect determines one or more test patterns and time duration for testing the new memory unit that replaced a failed memory unit. The test pattern is written to the new memory unit and read from the new memory unit. The read pattern is compared to the test pattern that was used to write. If the read test pattern and the written test pattern doe not match, a further repair action is taken. If they match, writing and reading of the test pattern repeats until the time duration for testing expires. The new memory unit may be configured as available for use when the write and read test completes successfully for the testing time duration.