Перед установкой может потребоваться:

sudo apt-get install libtommath1 libtommath-dev
sudo ln -s /usr/lib/x86_64-linux-gnu/libtommath.so.1.0.1 /usr/lib/x86_64-linux-gnu/libtommath.so.0

sudo systemctl stop firebird-superserver.service
sudo systemctl start firebird-superserver.service
sudo systemctl restart firebird-superserver.service
sudo systemctl status firebird-superserver.service

sudo systemctl stop firebird-classic.socket
sudo systemctl start firebird-classic.socket
sudo systemctl status firebird-classic.socket
sudo systemctl reset-failed

sudo /opt/firebird/bin/gfix -online uvrdmes
sudo /opt/firebird/bin/gfix -shutdown -force 5 uvrdmes

sudo ./fbsvcmgr service_mgr -user sysdba -password masterkey -info_server_version -info_implementation
sudo ./fbsvcmgr service_mgr -user sysdba -password masterkey -action_display_user

systemd-analyze
systemd-analyze blame
systemd-analyze critical-chain
systemctl list-unit-files

sudo apt-get install libicu52  

sudo su
echo "deb http://security.ubuntu.com/ubuntu focal-security main universe" > /etc/apt/sources.list.d/ubuntu-focal-sources.list
apt update
apt upgrade
apt install libncurses5
apt install libtommath1
ln -s libtommath.so.1 /usr/lib/x86_64-linux-gnu/libtommath.so.0
init 6

sudo /opt/firebird/bin/changeServerMode.sh