The SFTP server is only installed when you choose the "Monitoring Node" option on the installer.
Many of our customers do not want this SFTP server installed so they simply choose the "Managing Node" at the time of installation for all nodes if they do not want it installed. Related... in 11.1 forward it "UC Reporter" is no longer a selectable option and it automatically installs it and there is no way of preventing that even if you do not want it or not a UC customer.
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Christopher R Souser - Solution Architect – MSci. PA, CISSP, ITIL.