ZenPack to monitor activity on HardDisk components modeled by zenoss.snmp.UCDHardDiskMap using UCD-DISKIO-MIB
The block device load average OIDs (diskIOLAn) require Net-SNMP 5.5 or newer on the target host, and Linux distributions based on Debian 8 and Enterprise Linux 6 (or newer) are known to work.
Activity and throughput metrics will still work on older releases.
Requires ZenPackLib
This doesn't (yet) modify modeler plugins on any device class like /Server/Linux, so it's up to you to apply the zenoss.snmp.UCDHardDiskMap modeler on the appropriate class or device.