I would like to upgrade a server that is currently running Firebird 2.1 to Firebird 2.5.0.26074

I have obtained the appropriate package, backed up relevant user databases, and taken a copy of the security2.fdb.

The Firebird 2.1 service is still running, so when I issue a:
sudo ./install.sh

I receive a "An instance of the Firebird Super Server seems to be running.".

So, I issue the following to stop the 2.1 installation:
/etc/init.d/firebird2.1-super stop

I then return and re-run the "sudo ./install.sh"
This runs through successfully this time, but includes many references to "insserve" and missing LSB tags and overrides. Is this a problem?

I insert an appropriate password and receive an "Install complete" message.

Now, when I refer to /etc/init.d I see a new reference to "firebird".
Unfortunately, my system still seems to be running 2.1 rather than 2.5 could someone please provide me with some guidance / explanation?

Thank you