Upgrade to CentOS and add 2 nodes to existing
Est. elapse: 4 weeks (start 7/31, Wed?); Est. labor: 120 hours
Pull an old CN and convert to CentOS HD ("new HN")
Add new CNs to new HN
Add old CN's to new HN
Convert old HN to CN and add it to new HN
Later; see
P41
: Migrate to ChemIT Community Head Node
Add all CN's to ChemIT Community HN
Convert Collum HN to CN and add to ChemIT Community HN