SNMP file system data from infoblox DDI seems to be useless for monitoring

[#1]

I am using CheckMK(a monitoring system) to monitor an infobox DDI by snmp. The items include file system info, such as /etc/ ( 80.34% used), /etc/resolv.conf (80.34% used)... The left space is not much and the warning occur. 
Do these warning make sense? Are the snmp data useful?

[#2]

On infoblox dashboard, there is aslo the "Disk Usage", is this enough for monitoring the disk space?