Linux how to start "sftp-server"?

view story

http://stackoverflow.com – I'm not very familiar with it but there is installed openssh/sftp-server (by a vendor before) on RHEL and it was well running before i reboot the server. Then when i check after rebooted: # ps aux | grep ftp No sftp is running but sshd is. So how do i do to have this sftp running please? (HowTos)