I have read the link but I was unable to resolve my problem. Currently my Dolibarr 8.0.1 in AWS is running under Debian 9, so should I follow the instruction for Debian?
I refer to the page, for Debian OS, it recommands to follow the Installation process... is it right for me?
"DoliDeb (Debian or Ubuntu .deb package)
First make a backup of your current installation
Process to upgrade using Debian/Ubuntu package is same way than install process (see previous chapters), so it is as easy as installing a package. You can also read page Dolibarr for Ubuntu or Debian."