Devices using the 'UC Davis Memory' Vendor Cert Return Negative Values

Products

• Network Observability
• CA Performance Management

Issue/Introduction

You observe corrupted, negative, or nonsensical memory metric values (e.g., im_Total showing as a large negative number, utilization exceeding 100%) for a device in DX NetOps Performance Management, despite the device reporting valid memory statistics at the hardware level.

Environment

DX NetOps Performance Management

Cause

The Data Collector interprets 32-bit SNMP memory OID values as signed integers. When a server's total memory exceeds the capacity of a signed 32-bit integer, the calculation results in negative values.

Resolution

Check to see if the device supports the UC Davis 64bit Memory counters (See Additional Information Section).


you must instruct the Data Aggregator to use 64-bit OIDs (which support larger memory values) by adjusting the Vendor Certification priority.

1. Log in to your Performance Management web console.
2. Navigate to the Metric Families section for the affected device.
3. Locate the two Vendor Certifications: "UC Davis Memory" and "UC Davis Memory 64".
   
   
   
   
   
4. Modify the priority for "UC Davis Memory 64" so that it has a higher priority (a lower numerical value, e.g., 19) than the standard "UC Davis Memory" (e.g., 20).
   
   
   
   
   
   
5. Trigger an Update Metric Family operation for the device.
   
   
   
   
   
6. Allow 2–3 polling cycles to pass.
   
   
7. Verify that the device now utilizes the "UC Davis Memory 64" metric family and that memory metrics report positive, expected values.

If the issue persists after these steps, please contact your Support Engineer (SE) to verify if additional metric family adjustments or custom OID configurations are required for your specific device model.

Additional Information If you need further details on how to manage metric families or vendor certifications, refer to the DX NetOps Performance Management Documentation. You can download the latest updates and patches from the Broadcom Support Portal.

Additional Information

Run a sapwalk against the device in question (see KB below)

Check for the 64bit UC Davis memory counters

memTotalRealX 1.3.6.1.4.1.2021.4.20 
memAvailRealX 1.3.6.1.4.1.2021.4.21 


How to generate a MIB dump using sapwalk2 / sapwalk