ZSH and Unraid

This set of instructions is 95% based on this reddit thread (see below for an archived version if the link doesn't work)
Install un-get plugin (using plugin manager, copy and paste the raw link to the .plg from github)
Install zsh:
un-get update && un-get install zsh
Install User Scripts plugin (in Community Applications)
edit 
/boot/config/go and add the following to the file:
# Install Oh-My-Zsh 
HOME="/root" sh -c "$(wget https://raw.githubusercontent.com/robbyrussell/oh-my-zsh/master/tools/install.sh -O -)" 
Create your .zshrc file at 
/boot/config/extra/.zshrc:
export ZSH="/root/.oh-my-zsh"
ZSH_THEME="robbyrussell"
DISABLE_UPDATE_PROMPT="true"
HISTSIZE=10000
SAVEHIST=10000
HISTFILE=/root/.cache/zsh/history
plugins=(
  zsh-autosuggestions
  zsh-syntax-highlighting
)
source $ZSH/oh-my-zsh.sh
# User configurations
alias l='ls -lFh'     #size,show type,human readable
alias la='ls -lAFh'   #long list,show almost all,show type,human readable
Create a new script named "zsh" in user scripts and set it to "At Startup of Array" 
Edit the script you just created 
/boot/config/plugins/user.scripts/scripts/zsh/script
#!/bin/bash
HOME=/root
OH_MY_ZSH_ROOT="$HOME/.oh-my-zsh"
ZSH_CUSTOM="$HOME/.oh-my-zsh/custom"
OH_MY_ZSH_PLUGINS="$ZSH_CUSTOM/plugins"
OH_MY_ZSH_THEMES="$ZSH_CUSTOM/themes"
mkdir -p $OH_MY_ZSH_PLUGINS
mkdir -p $OH_MY_ZSH_THEMES
# Install zsh-autosuggestions
if [ ! -d "$OH_MY_ZSH_PLUGINS/zsh-autosuggestions" ]; then
        echo "  -> Installing zsh-autosuggestions..."
        git clone https://github.com/zsh-users/zsh-autosuggestions $OH_MY_ZSH_PLUGINS/zsh-autosuggestions
else
        echo "  -> zsh-autosuggestions already installed"
fi
# Install zsh-syntax-highlighting
if [ ! -d "$OH_MY_ZSH_PLUGINS/zsh-syntax-highlighting" ]; then
        echo "  -> Installing zsh-syntax-highlighting..."
        git clone https://github.com/zsh-users/zsh-syntax-highlighting.git $OH_MY_ZSH_PLUGINS/zsh-syntax-highlighting
else
        echo "  -> zsh-syntax-highlighting already installed"
fi
chmod 755 $OH_MY_ZSH_PLUGINS/zsh-autosuggestions
chmod 755 $OH_MY_ZSH_PLUGINS/zsh-syntax-highlighting
chsh -s /bin/zsh
# Remove oh-my-zsh default .zshrc
rm /root/.zshrc
# Make sure the necessary directories are existing
mkdir -p /root/.cache/zsh/
mkdir -p /boot/config/extra/
# Make sure history file exists
touch /boot/config/extra/history
# Symlink .zshrc and history files
cp -sf /boot/config/extra/.zshrc /root/.zshrc
cp -sf /boot/config/extra/history /root/.cache/zsh/history
 Reboot your server and you should now have zsh setup (or run the scripts manually and create .zshrc file in /root/)
References
ZSH with persistent config, history and oh-my-zsh, /r/unraid (Archived Version)