Bit of an open-ended question here sorry, hence why it's a CW, it's to help inform some toolset writers that I work with what direction to go with their new product, hope you don't mind.
If you could create your own management tool for your VMWare hosts, and optionally vCenter/s, are there any stats/reports/information that you'd like to get that you either can't using current tools or that are hard to get at or combine?
For instance I'm unaware of any built in tools to let me know how many IOPS per LUN or array any given cluster, data center or VC is using, I had to buy vCenter Operations to get at that easily. What else would be good info/reports to get at that are hard to get now?
A report that shows files that aren't connected to a VM.
A report that shows all snapshots and the size they take up (I currently have to check PowerCLI for this information).
An overview of reserved, allocated, ballooned, and actual consumed memory per-VM and per-Host :)
I know there are reports in vCenter that will provide some of these, but not all together, not for all Hosts, and not all of this data at once...
*note that I am running 4.1, so maybe this has been fixed in 5.
I would love to see how much memory is being used form the guests perspective. Meaning if a windows guest has 8GB and it thinks it using 6GB, i'd love to see that.