At time of writing this article, most of the guides I've found concerning the installation of Plex on a Raspberry Pi recommend using the Raspberry Pi compatible Raspbian/Debian package offered by dev2day. The work by dev2day provides a simple and easy way to install the Plex server on a Raspberry Pi.

I recommend using the dev2day package repository and instructions for a pain-free installation process. My process, written below, is manual and untested.

Despite that warning, if you're like me and hate ever adding third party repositories to your machine, you can manually install Plex on a Raspberry Pi 3 using the instructions below. All the steps below are based entirely on dev2day's work.

Download the Synology package for ARMv7 from the Plex Media Server Downloads page to your Raspberry Pi. You can curl the download URL on your Pi like so.

curl \
    -o plex.tar \
    "https://downloads.plex.tv/plex-media-server/1.14.0.5470-9d51fdfaa/PlexMediaServer-1.14.0.5470-9d51fdfaa-arm7.spk"

Create a destination directory for the Plex server files.

sudo mkdir -p /usr/lib/plexmediaserver

The plex.tar archive is a Synology package, and the file structure inside plex.tar looks like this.

INFO  PACKAGE_ICON.PNG  package.tgz  plex.tar  scripts  syno_signature.asc

What we want is the package.tgz file. We can extract it directly to our desintation directory using this command which will run as root.

sudo su -c 'tar -xOf plex.tar package.tgz | tar -xzf - -C /usr/lib/plexmediaserver'

Create a config file at /etc/default/plexmediaserver like so. Note that these are all the defaults as of time of writing.

# /etc/default/plexmediaserver

# the number of plugins that can run at the same time
PLEX_MEDIA_SERVER_MAX_PLUGIN_PROCS=6

# ulimit -s $PLEX_MEDIA_SERVER_MAX_STACK_SIZE
PLEX_MEDIA_SERVER_MAX_STACK_SIZE=3000

# where the mediaserver should store the transcodes
PLEX_MEDIA_SERVER_TMPDIR=/tmp

# uncomment to set it to something else
# PLEX_MEDIA_SERVER_APPLICATION_SUPPORT_DIR="${HOME}/Library/Application\ Support"

# the user that PMS should run as, defaults to 'plex'
# note that if you change this you might need to move
# the Application Support directory to not lose your
# media library
PLEX_MEDIA_SERVER_USER=plex

Create a plex user, which will be used for running the Plex Media Server (PMS) process.

sudo adduser \
    --quiet \
    --system \
    --shell /bin/bash \
    --home /var/lib/plexmediaserver \
    --group plex

Add the plex user to the video group.

sudo gpasswd -a plex video

Create a systemd service control file at /lib/systemd/system/plexmediaserver.service like so.

[Unit]
Description=Plex Media Server for Linux
After=network-online.target

[Service]
Environment="PLEX_MEDIA_SERVER_APPLICATION_SUPPORT_DIR=/var/lib/plexmediaserver/Library/Application Support"
Environment=PLEX_MEDIA_SERVER_HOME=/usr/lib/plexmediaserver
Environment=PLEX_MEDIA_SERVER_MAX_PLUGIN_PROCS=6
Environment=PLEX_MEDIA_SERVER_TMPDIR=/tmp
ExecStartPre=/bin/sh -c '/usr/bin/test -d "${PLEX_MEDIA_SERVER_APPLICATION_SUPPORT_DIR}" || /bin/mkdir -p "${PLEX_MEDIA_SERVER_APPLICATION_SUPPORT_DIR}"'
ExecStart=/bin/sh -c 'LD_LIBRARY_PATH=/usr/lib/plexmediaserver "/usr/lib/plexmediaserver/Plex Media Server"'
Type=simple
User=plex
Group=plex
Restart=on-failure
RestartSec=5
StartLimitInterval=60s
StartLimitBurst=3

[Install]
WantedBy=multi-user.target

Start the plexmediaserver service.

sudo systemctl start plexmediaserver

Enable the plexmediaserver service at boot.

sudo systemctl enable plexmediaserver

Navigate to the IP address of your Pi in a web browser to start using Plex. The URL should look something like this. Note, it may take a few seconds before Plex starts and this link works.

http://192.168.1.101:32400/web/