# Fully sync MainNet from Legacy to Current

It is entirely possible - should you wish - to set up and fully sync a MainNet node from the original FUND-Mainchain-MainNet-v1 genesis, right up to the current block.

This guide will cover the necessary steps for those who prefer to do so.


To fully sync the chain from FUND-Mainchain-MainNet-v1 will take several days (or weeks) and require a significant amount of disk space! Ensure you have at least 300Gb disk space available to allow for syncs, and upwards of 500Gb if backups are required.

There are several steps required, some of which will require manual intervention:

  1. Initialise the node using und v1.4.8 & Synchronise from FUND-Mainchain-MainNet-v1 genesis to block 11,039,060
  2. Export and migrate the state from block 11,039,060 to the FUND-MainNet-2 genesis using und v1.4.9
  3. Set up and initialise Cosmovisor, and the current und binaries (v1.5.x, v1.6.x etc.)
  4. Sync from FUND-MainNet-2 genesis to the current block

# 1. Initialise & sync FUND-Mainchain-MainNet-v1

FUND-Mainchain-MainNet-v1 ran for just over 2 years, and resulted in 11,039,060 blocks. The first step is to initialise your node using und v1.4.8, and synchronise it from genesis to block 11,039,060. In addition to the Legacy RPC, REST and Explorers, the Unification Foundation maintains a Legacy node dedicated to P2P to allow for this.

# Install dependencies

Update, e.g.

sudo apt update -y

git and make are required dependencies for building. curl and/or wget are recommended, and jq is useful for quickly looking up values in, for example genesis.json

These can all be installed via your package manager, for example:

sudo apt-get install git curl wget make jq


sudo yum install git curl wget make jq

# Download und v1.4.8

Download and install und v1.4.8:

cd $HOME
mkdir -p legacy/v1.4.8 && cd legacy/v1.4.8
wget https://github.com/unification-com/mainchain/releases/download/1.4.8/und_v1.4.8_linux_x86_64.tar.gz
tar -zxvf und_v1.4.8_linux_x86_64.tar.gz

# Initialise your node

Next, initialise the node and its configuration files:

$HOME/legacy/v1.4.8/und init my-node

Modify my-node accordingly, to a suitable moniker for your node.

# Download and check FUND-Mainchain-MainNet-v1 genesis

We'll need the FUND-Mainchain-MainNet-v1 genesis file to start with:

curl https://raw.githubusercontent.com/unification-com/mainnet/master/legacy/0.38/latest/genesis.json > $HOME/.und_mainchain/config/genesis.json

and check the Chain ID is FUND-Mainchain-MainNet-v1:

jq --raw-output '.chain_id' $HOME/.und_mainchain/config/genesis.json

# Configure P2P connection

There are no seed nodes for FUND-Mainchain-MainNet-v1. Instead, we'll set the Foundation's Legacy P2P node as a persistent peer. Open $HOME/.und_mainchain/config/config.toml with a text editor, for example nano:

nano $HOME/.und_mainchain/config/config.toml

In the [p2p] section, set persistent_peers as follows, and save:

persistent_peers = "6e9fe5b2aed55bc322d8a90a8a011b45c70c076d@legacy-fund-mainnet-v1-p2p.unification.io:26656"

# Configure Application settings

Next, the app.toml needs some configuring:

nano $HOME/.und_mainchain/config/app.toml

Find and set the following values:

minimum-gas-prices = "0.25nund"
halt-height = 11039060
pruning = "everything"

# Configure und to run as a systemd service

To allow und to run as a background service, it's recommended to create and maintain a systemd service. Create the service file:

sudo nano /etc/systemd/system/und.service

Containing the following minimal configuration:

Description=Unification Mainchain Validator Node

ExecStart=/home/ubuntu/legacy/v1.4.8/und start


Modify as required, taking particular notice to the User, Group, WorkingDirectory and ExecStart values.

Finally, install the service:

sudo systemctl daemon-reload
sudo systemctl enable und

and run it:

sudo systemctl start und

You can now monitor the sync progress with:

sudo journalctl -u und -f

Once it reaches block 11,039,060, the node will stop and exit.

# 2. Export and Migrate FUND-Mainchain-MainNet-v1 to FUND-MainNet-2


Do not proceed with the following steps until your node has fully synced up to block 11,039,060. Doing so will result in an incorrect FUND-MainNet-2 genesis export! Do not stop the node until you see the following in the journalctl logs:

halting node per configuration               module=main height=11039060 time=0
Committed state                              module=state height=11039060 txs=0 appHash=EB8ECEBAC7D1B84B459BA5541C108B3687C045E340B2D4044638E23A7F06009B

Fully syncing the legacy chain will take several days, if not weeks to complete!

Once FUND-Mainchain-MainNet-v1 has been fully synced, it will be possible to run the first upgrade. This upgrade was originally run on Wednesday 8th June 2022 at 11:00:00 GMT+0000, and the exact steps run by validators will be implemented here.

Stop the systemd service:

sudo systemctl stop und

# Optionally backup the .und_mainchain directory

Backups are always a good idea. Use rsync, or tar to backup, for example:

rsync -av $HOME/.und_mainchain/ $HOME/und_mainchain_BAK/


cd $HOME/.und_mainchain
tar -cpzf $HOME/und_mainchain.backup.tar.gz *

The backup may consume 90Gb - 150Gb disk space, but can be deleted after a successful upgrade/migration.

# Download und v1.4.9

und v1.4.9 was used to export the FUND-Mainchain-MainNet-v1 chain state to a new genesis.

cd $HOME
mkdir -p legacy/v1.4.9 && cd legacy/v1.4.9
wget https://github.com/unification-com/mainchain/releases/download/1.4.9/und_v1.4.9_linux_x86_64.tar.gz
tar -zxvf und_v1.4.9_linux_x86_64.tar.gz

# Export the FUND-Mainchain-MainNet-v1 chain state

Export the current chain state to the new genesis. Effectively, all accounts, wallets, balances and all other chain data at block 11,039,060 were exported to a new genesis block, such that the entire chain state at block 11,039,060 becomes the new block 0 for FUND-MainNet-2.

You must use und v1.4.9 to execute this:

$HOME/legacy/v1.4.9/und export --for-zero-height --home=$HOME/.und_mainchain > $HOME/v038_exported_state.json

# Download und v1.5.1

und v1.5.1 was used to migrate the exported FUND-Mainchain-MainNet-v1 chain state to the FUND-MainNet-2 genesis, and to run the new chain up to block 2,002,620.

cd $HOME
mkdir -p upgrade/v1.5.1 && cd upgrade/v1.5.1
wget https://github.com/unification-com/mainchain/releases/download/1.5.1/und_v1.5.1_linux_x86_64.tar.gz
tar -zxvf und_v1.5.1_linux_x86_64.tar.gz

# Migrate FUND-Mainchain-MainNet-v1 to FUND-MainNet-2

Next, we need to migrate the exported FUND-Mainchain-MainNet-v1 chain state data to the new FUND-MainNet-2 genesis, using und v1.5.1:

$HOME/upgrade/v1.5.1/und migrate $HOME/v038_exported_state.json --chain-id=FUND-MainNet-2 --genesis-time="2022-06-08T14:00:00Z" --log_level="" > $HOME/new_v042_genesis.json

Validate the migrated genesis:

$HOME/upgrade/v1.5.1/und validate-genesis --log_level="" $HOME/new_v042_genesis.json

should result in:

File at new_v042_genesis.json is a valid genesis file

Generate a checksum:

jq -S -c -M '' $HOME/new_v042_genesis.json | sha256sum

it should result in:


Reset the chain data for your node:

$HOME/upgrade/v1.5.1/und unsafe-reset-all --log_level="" --home=$HOME/.und_mainchain

Copy the new genesis file to replace the old version in $HOME/.und_mainchain/config:

cp $HOME/new_v042_genesis.json $HOME/.und_mainchain/config/genesis.json

Download the new Cosmos SDK v0.42 formatted app.toml and replace your old version in $HOME/.und_mainchain/config:

curl https://raw.githubusercontent.com/unification-com/mainnet/master/latest/042_app.toml > $HOME/.und_mainchain/config/app.toml

Modify as required:

nano $HOME/.und_mainchain/config/app.toml

To aid the network, it's worth setting some values in the [state-sync] section in app.toml, for example:

snapshot-interval = 500
snapshot-keep-recent = 4

Finally, change the log_level in $HOME/.und_mainchain/config/config.toml, as the variable format has changed in Cosmos SDK 0.42.x, and modify the sseds and `persistent_peers:

nano $HOME/.und_mainchain/config/config.toml


log_level = "info"

also, in the [p2p] section, set:

seeds = "[email protected]:26656,[email protected]:26656"

persistent_peers = ""

Note: if you have a list of persistent_peers, you can add them too.

# 3. Configure and Migrate to Cosmovisor

Now that the fundamentals are in place, we can migrate the running and management of the und daemon to Cosmovisor, and continue syncing the chain until it's up-to-date.

# Install Cosmovisor

First, install cosmovisor

mkdir $HOME/tmp && cd $HOME/tmp
wget https://github.com/cosmos/cosmos-sdk/releases/download/cosmovisor%2Fv1.5.0/cosmovisor-v1.5.0-linux-amd64.tar.gz
tar -zxvf cosmovisor-v1.5.0-linux-amd64.tar.gz
sudo mv cosmovisor /usr/local/bin/cosmovisor

# Set up cosmovisor directory structure

Next, we need to set up some directories and und binaries for Cosmovisor to work with:

# und v1.5.1 -> genesis:

mkdir -p $HOME/.und_mainchain/cosmovisor/genesis/bin
mv $HOME/upgrade/v1.5.1/und $HOME/.und_mainchain/cosmovisor/genesis/bin

# und v1.6.x -> 1-init_ibc update

mkdir -p $HOME/upgrade/v1.6.3 && cd $HOME/upgrade/v1.6.3
wget https://github.com/unification-com/mainchain/releases/download/v1.6.3/und_v1.6.3_linux_x86_64.tar.gz
tar -zxvf und_v1.6.3_linux_x86_64.tar.gz
mkdir -p $HOME/.und_mainchain/cosmovisor/upgrades/1-init_ibc/bin
mv und $HOME/.und_mainchain/cosmovisor/upgrades/1-init_ibc/bin

# Create cosmovisor environment file

Create an environment variable file which will load into the systemd service, modifying /FULL/PATH/TO/ as required:

tee $HOME/.und_mainchain/cosmovisor/UND_COSMOVISOR_ENV > /dev/null <<EOF

# Edit systemd service file

Open the und.service file in a text editor

sudo nano /etc/systemd/system/und.service

Add the EnvironmentFile directive to the [Service] section using the full, absolute path to UND_COSMOVISOR_ENV, for example:


Edit the ExecStart directive, replacing /path/to/und start with /usr/local/bin/cosmovisor run, for example:


ExecStart=/home/ubuntu/legacy/v1.4.8/und start


ExecStart=/usr/local/bin/cosmovisor run start

Your service file should now look something along the lines of:

Description=Unification Mainchain Validator Node

ExecStart=/usr/local/bin/cosmovisor run start


# 4. Reload the daemon and sync!

Finally, we can reload the systemd service file changes:

sudo systemctl daemon-reload

then restart the und service:

sudo systemctl start und

Finally, monitor progress with:

sudo journalctl -u und -f

Cosmovisor will automatically handle any upgrades (for example, v1.5.1 -> v1.6.x).

Note: your node may still take several more days to fully sync!