SRP modules include error checking and correction (ECC) to protect their SDRAM. ECC provides error detection of single-bit and double-bit errors and correction of single-bit errors for the SDRAM as follows:
The following message appears on the console when ECC detects a double-bit error:
ALERT 05/10/2004 13:10:33 os: failed: ECC DOUBLE BIT ERROR OCCURRED Address = 0xe95db10 Data (Upper 32Bits) = 0xe95db20 Data (Lower 32Bits) = 0x55d06c ECC Data Bits = 0x2b ECC 1Bit Error Counter = 0x0 *** YOU MUST PERFORM A HARD RESET TO CONTINUE *** ALERT 05/10/2004 13:10:34 os: PROCESSOR EXCEPTION: 0x200n
When ECC detects a double-bit error in a system that contains a redundant SRP module, the redundant module becomes active and the system continues to operate. However, you must still troubleshoot the SRP module with the double-bit error. When ECC detects a double-bit error in a system that does not contain a redundant SRP module, you must troubleshoot the SRP module immediately. See Fixing Double-Bit Errors.
To fix a double-bit error:
These actions attempt to correct a transient double-bit error. However, if the console displays a memory test failure for the SRP module after you reboot, or if the FAIL LED on the SRP module stays on during rebooting, the SDRAM is permanently damaged and needs replacing. In this event, call the Juniper Networks Technical Assistance Center to arrange for repair.