Upgrading proftpd is usually a straightforward process, but as with any upgrade, double-checking that the upgrade will not break anything is a Good Idea.
proftpd
Recent ProFTPD releases have a RELEASE_NOTES file in the source distribution that documents the changes in that release, including new configuration directives, new contrib modules, deprecated directives, special instructions, etc. In addition, the NEWS file contains a list of the bugs that have fixed, and comments about any changes the bugfix required. Please read these files carefully before starting your upgrade.
RELEASE_NOTES
NEWS
One safe way to test the upgrade is to compile the new proftpd, and test it out on your existing configuration file before actually installing the new version into the "live" location:
$ tar zxvf proftpd-version.tar.gz $ cd proftpd-version/ $ ./configure .. $ make $ ./proftpd -t -d10 -c /path/to/proftpd.conf
./proftpd
make
proftpd.conf
$ cp /path/to/proftpd.conf /path/to/proftpd.conf.new
proftpd.conf.new
$ ./proftpd -t -d10 -c /path/to/proftpd.conf.new
Once everything is configured the way you like, install the new binary and configuration file:
$ make install $ cp /path/to/proftpd.conf /path/to/proftpd.conf.old $ mv /path/to/proftpd.conf.new /path/to/proftpd.conf