Hi @wcndave. While the Raspberry Pi 3 Model B+ features a 64 bit ARM processor, the operating system Raspbian 9.4 (stretch) is compiled for 32 bit (armv7l). Thus, the version of Grafana you need to install is the ARMv7 version “grafana_5.2.2_armhf.deb”, Grafana 5.2.2 being the current stable version at the time of this writing (2018-08-20).
Currently, neither the ARM64 nor the ARMv7 are available from the Grafana Debian repository at packagecloud.io/grafana. This means that the installation method “APT Repository” will not work. Instead you’ll need to follow the steps described in “Install Stable” as follows:
sudo apt-get install -y adduser libfontconfig # I’m not sure this is needed
sudo dpkg -i grafana_5.2.2_armhf.deb
This is the installation procedure that worked for me, hope it helps.