Install BTCPayServer on Raspberry Pi with Pruning and Fast Sync

BTCPi

Order from Lightning in a Box https://lightninginabox.co/product/btcpi/

or 

Visit BTCPi.com for DIY instructions. 



The folloiwng are very old instructions to install BTCPayServer on a Raspberry Pi 3.  Please ignore 

These instructions assume that you are starting with "virgin" Raspberry Pi Model 3 B+ that is running the latest updated version 
of Raspbian Stretch. https://downloads.raspberrypi.org/raspbian_lite_latest

Requirements:
- Raspberry Pi 3 B+
- Minimum 64 Gb SD Cardif no flash drive, 8 Gb minimum SD Card if you have a flash drive
- 64 Gb USB Flash Drive (optional)
- Sub domain pointed to "btcpay.mydomain.com"
- Static External IP Address
- Forward ports 80,443,8333,9735 on your router to the Raspberry Pi

1. SSH to Raspberry Pi

2. Switch to root
sudo su -

3. Because running a node involves a lot of I/O it's recommended that you store the blockchain on a flash drive 
instead of the SD card.  If you don't have a USB flash drive you can skip to the Step 5. 

The command 'fdisk -l' shows a list of the connected storage devices. Assuming you only have one flash drive connected it will be
called /dev/sda.  Double check that the /dev/sda exists and the storage capacity matches your device. 

#Format and mount flash drive
#Delete existing partition(s)
fdisk /dev/sda
d
w

#create new primary partition
fdisk /dev/sda
n
p
1
enter
enter
w

#Format partition as ext4
mkfs.ext4 /dev/sda1

#create folder for mount
mkdir /mnt/usb

#Look up UUID of flash drive
blkid -o list

#Add mount to fstab
nano /etc/fstab

#Add the following line to the end of the fstab file
UUID=(UUID of flash drive do not include parenthesis) /mnt/usb ext4 defaults,nofail 0

#test fstab file
mount -a

#check to see if drive is mounted. 
df -h

#/dev/sda1 should be mounted on /mnt/usb


#Create symlink to flash drive for Docker
mkdir /mnt/usb/docker
ln -s /var/lib/docker /mnt/usb/docker

5. Create a folder for BTCPay
mkdir BTCPayServer
cd BTCPayServer

6. Clone this repository
git clone https://github.com/btcpayserver/btcpayserver-docker
cd btcpayserver-docker

7. Run btcpay-setup.sh with the right parameters
export BTCPAY_HOST="btcpay.mydomain.com"
export NBITCOIN_NETWORK="mainnet"
export BTCPAYGEN_CRYPTO1="btc"
export BTCPAYGEN_REVERSEPROXY="nginx"
export BTCPAYGEN_LIGHTNING="lnd"
export BTCPAYGEN_ADDITIONAL_FRAGMENTS="opt-save-storage-xs;opt-save-memory"
. ./btcpay-setup.sh -i

BTCPayServer's FastSync documentation is available here https://github.com/btcpayserver/btcpayserver-docker/tree/master/contrib/FastSync.
Please read very carefully to understand what FastSync is and why it's important to verify the UTXO set yourself.

Allow BTCPayServer run for a few minutes and visit your website (https://btcpay.mydomain.com) to confirm BTCPayServer is running.

8. From the /root/BTCPayServer/btcpayserver-docker folder run the following commands.
./btcpay-down.sh
cd contrib
cd FastSync
./load-utxo-set.sh

9. This will take about 30 minutes or so depending on your download speed. After FastSync finishes run the following command.
./btcpay-up.sh

Visit your domain and you should now see that your sync is at least 99%.
Enjoy!