We have cluster having 8 host under it running with esxi 4.1, and each host attached with approx 200+datastore/luns
my concern is while we do upgrade form Esxi 4.1 to Esxi 5.1 (will do one by one for each host in cluster)
will there be any impact for the luns attached to each of my hosts ?
what are the best practice/recommendation/concern we have to check before upgrading host ?
will vmfs also upgrade during host upgrade ?
if yes..how those luns will be visible for other hosts in same cluster running with 4.1 ?
Please advice best practice to upgrade 4.1 to 5.1 with minimal downtime(we are moving all existing host form vc 4.1 to 5.1 then we will do upgrade one by one)