Harvest supports capacity monitoring exclusively via OCUM. I made this choice because:
1) Everyone should use OCUM. It provides monitoring, trending, alerting, and more, at no additional cost.
2) Reduce collection load on the cluster. Since OCUM is already collecting and storing the data we can avoid any additional collection load on the cluster.
3) Time; I only have so much to implement things 🙂
I am working on another feature (mapping vols under aggrs, in addition to vols under svms as today) but this will also require OCUM. So if you can let me know why you don't want to use OCUM that would be helpful for me to understand.
Cheers, Chris Madden
Storage Architect, NetApp EMEA (and author of Harvest)
thanks for your detailed reply. The original reason behind my question was to be sure I need to set up OCUM to get the storage capacity metrics, so you clearly replied yes 🙂 What you wrote is sensible, especially about avoiding the extra collection load on the cluster. Given that OCUM adds value to monitoring and to the infrastructure in general, I will go on and set it up. Thank you!