If you want to locate logs from ESX from storage perspective :
Location is :
1. SSH to Host
2. Goto /var/log directory
3. You will find vmkernel.log file, which will have all storage related logs .
Along with that you can find SIOC(Storage IO control ) i.e storagerm.log, FDM related fdm.log (fault domain manager) + several other components log under the same directory.
Hope this helps