Based on https://wikitech.wikimedia.org/wiki/Switch_Datacenter#Manual_switch and https://wikitech.wikimedia.org/wiki/People.wikimedia.org#How_to_perform_a_switch-over_between_data_centers:

• find rsync_src_host and rsync_dest_host in /hieradata/role/common/microsites/peopleweb.yaml
• SSH to dst_host (you should see a warning in motd) and run manual rsync command:
  • rsync -avp rsync://people1004.eqiad.wmnet:/people-home /home/
• Run puppet on dst_host
• In puppet hieradata the rsync_src_host and rsync_dest_host hosts need to be flipped: https://gerrit.wikimedia.org/r/959690
  • merge and deploy change to both people machines
  • check motd on both servers (should be swapped)
• The DNS discovery name peopleweb.discovery.wmnet needs to be switched from one backend to another: https://gerrit.wikimedia.org/r/959693
  • merge and deploy DNS change
• confirm new backend gets traffic (tail -f /var/log/apache2/*.log).
• Inform the users via a mailing list like "sre-at-large" (since that should cover shell users) that we switched