I have inherited an old server to maintain. It is still running Debian 8, and php 5.6. There is one application on this server that requires php 5.6. The application involved has NO documentation, and I didn't write it. If I upgrade this to Debian 9 (by changing sources) this will also install php 7, but also keep version 5.6 installed, correct? At that point, can I follow items 4 and 5 from this howto: https://www.howtoforge.com/tutorial...fig-3-from-debian-packages-on-debian-8-and-9/ to get php 8 installed? This server is NOT an ISPConfig Apache server. The application and website are hard coded into the Apache vhosts file. I'd have to set the php version in each Vhosts section. Once I get this site working on php 5.6 on Debian 9, I'd upgrade again to Debian 10. Would I have any issues after that upgrade since php8 would already be installed and working?