Troubleshooting ESX host storage issues begins with identifying how far reaching (the scope) the problem is. In many cases, a detected problem may be misidentified until the scope has been ascertained.
To identify the scope of the problem:
Verify that the storage device cannot be seen by any or a subset of the ESX cluster. If so, select the appropriate storage technology:
Verify that the ESX host cannot see the datastore:
For Fibre channel or iSCSI, see Troubleshooting please issue following command to validate LUN and datastore availability. 1. df -h 2. esxcfg-scsidevs -c 3. esxcfg-scsidevs -m