# The "Galileo" upgrade guide (v0.8.\* to v1.0.\*)

## Step 0 - Don't panic

At the point of the proposed upgrade, user will see the error message on the `cronosd` similar to the below:

```bash
ERR UPGRADE "v1.0.2" NEEDED at height: 6542800: {\"binaries\":{...."}}
```

**Don't panic** - The Chain will be paused to allow the majority of validators to upgrade. Validators and full node hosts will have to upgrade your Cronos nodes to the latest release binary.

### Backups

Before the upgrade, node hosts are encouraged to take a complete data backup. backup depends heavily on infrastructure, but generally, we can do this by backing up the `.cronos` directory.

It is critically important for validator operators to back-up the `.cronos/data/priv_validator_state.json` file after stopping the `cronosd` process. This file is updated every block as your validator participates in consensus rounds. It is a critical file needed to prevent double-signing if the upgrade fails and the previous chain needs to be restarted.

## Step 1 - Get the `v1.0.2` binary

To simplify the following step, we will be using **Linux-x86** for illustration. Binary for Mac Windows with different DB and architecture are also available [here](https://github.com/crypto-org-chain/cronos/releases/tag/v1.0.2).

* Terminate the `cronosd`; afterwards, download the `1.0.2` released binaries from github:

  ```bash
  $ curl -LOJ https://github.com/crypto-org-chain/cronos/releases/download/v1.0.2/cronos_1.0.2_Linux_x86_64.tar.gz
  $ tar -zxvf cronos_1.0.2_Linux_x86_64.tar.gz
  ```
*

{% hint style="info" %}
Remarks: If you have stated `cronosd` with *systemd* service, kindly stop it by

```bash
$ sudo systemctl stop cronosd
```

And replace the binary in the location where the `ExecStart` states in Systemd Unit file.
{% endhint %}

### Step 1.1 - Verify the version

You can verify the installation by checking the version of `cronosd`, the version should be`1.0.2`.

```bash
# check the version of cronosd
$ ./cronosd version
1.0.2
```

### Step 1.2 - Update `app.toml`

In this v1.0.2 upgrade, there are a few extra parameters that we would have to add to `.cronos/config/app.toml` under

* `config.toml` with the `db_backend` field;
* `app.toml` with the `app-db-backend` field.

**For `db_backend` :**

Kindly set the above config to `config/config.toml`in your our `.cronos` dir according to your current DB setting, for example:

```
db_backend = "goleveldb"
```

* For `app-db-backend` :

Kindly add

```
# AppDBBackend defines the database backend type to use for the application and snapshots DBs.
# An empty string indicates that a fallback will be used.
# First fallback is the deprecated compile-time types.DBBackend value.
# Second fallback (if the types.DBBackend also isn't set), is the db-backend value set in Tendermint's config.toml.
app-db-backend = ""
```

to `config/app.toml`in your our `.cronos` dir according to your current DB setting. 

## Step 2. - Run everything

We are ready to start the node join the network again with the new binary:

* Start `cronosd`, e.g.:

```bash
  $ ./cronosd start
```

{% hint style="info" %}
Remark: Once the `cronosd` is started we would see the message

```bash
applying upgrade "v1.0.2" at height: 6542800"
```

and there will be an iteration over the previous blockchain data. This process will take a while, which is depending on the size of the database and the hardware specs.
{% endhint %}

Afterwards, sit back and wait for the syncing process. You can query the node syncing status by

```bash
$ ./cronosd status 2>&1 | jq '.SyncInfo.catching_up'
```

If the above command returns `false`, it means that your node **is synced**; otherwise, it returns `true` and implies your node is still catching up.

At this step, you've successfully performed the "Galileo" upgrade!


---

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