Disk Drives in dashboard show no data to display

Products

• CA Performance Management - Usage and Administration
• DX NetOps

Issue/Introduction

Some of our disk drives/partitions , which are local, that show as monitored but display as "No Data to Display".

Environment

DX NetOps Performance Management

Cause

Very large drives are problematic

Resolution

The backing vendor cert for the device was "Host Resources Storage"  In doing detailed poll logging for a drive that shows "no data to display" we saw the following"

1.3.6.1.2.1.25.2.3.1.5.2 = -597393921 --> hrStorageSize
1.3.6.1.2.1.25.2.3.1.4.2 = 8192
1.3.6.1.2.1.25.2.3.1.6.2 = -614834769 ---> hrStorageUsed

 

The drive in question showing no data was 4TB.  There is a comment in the vendor cert that states the following:

 

<!--  Some agents have a problem with very large disks/partitions where the values returned can be
           negative because of wrapping/truncating issues.  This is a result of the MIB using integers to store
           these values and for large sizes an integer is not big enough.  Previously this was being handled via
           convertSignedIntToUnsigned() but this does not help as converting to unsigned does not necessarily give us
           an accurate value since the host could have truncated the original number to force it to an integer and
           the high-order bit might have been 1 after this truncation, signaling a signed value.
           Also, originally hrStorageSize was the only variable being checked for negative but a customer was seeing
           cases where Used was negative in the CAPC tables, which indicates hrStorageAllocationUnits was
           negative, as unlikely as that should be!  Because of this more variables than seem necessary are being
           checked for negative values.   -->

 

So this looks to be an agent issue with net-snmp.  Another agent like systemedge / APM-IA (Intfrastructure Agent = systemedge) would be needed to get this info