vSphere can show me this data, but with several caveats:
1) If I pick 'Datastore' as the 'chart option', then I can only look at 'real time'. I.e. I can't get historical data.
ok, then how about 'Disk'?
2) If I pick 'Disk' as the 'chart option', then I do have several date-range objects to select, but when I select a date-range object other than 'Real Time', 2 problems happen:
a) I can no longer select which disk I want to look at. The only disk presented is one named after the esxi host. I don't know what disk that really is.
b) I can no longer select a counter which gets me what I want (i.e. these counters are no longer available: 'Command/second', 'Average Reads/sec' or 'Average Writes/sec'.)
I know that resxtop can get me the info I want. I could wrap it inside a tool that will then graph the data (e.g. munin).
What about SNMP? I see that there are VMWare MIBs (http://pubs.vmware.com/vsphere-4-esx-vcenter/topic/com.vmware.vsphere.dcadmin.doc_41/vsp_dc_admin_guide/snmp_config/r_vmware_mib_files.html), but I can't figure out if any of them give me the data I want.
Thanks for your advice. Regards,
Jon