Use these commands to turn on diagnostic logging for information store
get-eventloglevel (this lists all services that can be logged extensively)
use the powershell commands below to set logging level (lowest, low, medium, expert)
set-eventloglevel -id ‘MSExchangeIS9002 SystemGeneral’ -level ‘expert’
set-eventloglevel -id ‘MSExchangeIS9000 privateGeneral’ -level ‘expert’