The filesystem metrics for Oracle agents were failing. The following error was found in the Oracle agent log:
Failed to execute the [echo QUEST_OUTPUT_START; df -Pk] script of DBO_OS_File_System_Disk on MYSERVER.MYDOMAIN.COM-PROD. Reason : [df: /PROD: There is an input or output error.].Unix Error code : 
When the database agent ran a "df" command as part of the OS-based collection the following error was found:
df: /PROD: There is an input or output error.