Upgrading Ubuntu 20.04 to Ubuntu 22.04

This guide is intended for all AppViewX customers that are currently using Ubuntu 20.04 operating system. It offers step-by-step instructions for transitioning from Ubuntu 20.04 to Ubuntu 22.04, covering essential pre-upgrade preparations, updating packages, configuring necessary repositories, and resolving compatibility issues with deprecated modules for a seamless upgrade. This process applies specifically to AppViewX-shipped OVAs.

Pre-Upgrade Considerations

Before starting the upgrade, ensure the following are addressed:

Backup: Take a VM snapshot before starting the upgrade to enable rollback in case of issues.
Internet Connectivity: Ensure the node has internet or proxy access to download the OS update from repos.appviewx.com.
Disk Space: Verify that at least 3GB of free space is available in the root (/) partition.
Current Version Check:Confirm that the system is running Ubuntu 20.04 by executing the following command:
- ```
lsb_release -a
```

Prerequisite

Stop AppViewX on All Nodes (On-Premise Setups Only).

Note: This step is applicable only to on-premise setups. Cloud Connectors (CC) do not require component stoppage.
1. Log in to the AppViewX installer node and navigate to the appviewx_kubernetes/scripts directory.
2. If you are upgrading the OS with a downtime, then use the following command to stop the AppViewX on all the nodes.
  1. For single-node:
```
./appviewx.sh --stop <hostname>
```
  2. For multi-node:
```
./appviewx.sh --stop -all
```
3. If you are upgrading the OS without a downtime, then use the following command to stop the AppViewX nodes.
  - For multi-node - This applies only to multi-node clusters. For multi-master clusters, ensure that the master load balancer is properly configured to prevent downtime.
```
./appviewx.sh –stop <hostname>
```
  - Before proceeding to the next node, upgrade the OS and verify that the components are running on the node using:
```
kubectl get pods -A -o wide | grep -i <hostname>
```
  Note: Use VMware Console access for this upgrade. If upgrading over SSH, use "screen" or "tmux" to prevent interruptions in case of disconnection.
Check if the tmux package is installed on your node. If not, install it using
```
sudo apt install tmux
```
Attach to a tmux session by running:
```
tmux
```

Preparing for the Upgrade

To prepare for the upgrade, update all installed packages on Ubuntu 20.04. Execute the following commands:

```
sudo apt update -y
```
```
sudo apt upgrade -y
```
Note: If there is an error on executing the above command as shown below then execute the following command:
```
sudo apt --fix-broken install -y
```
After the apt --fix-broken install command executes successfully, execute the apt upgrade command once again.
```
sudo apt upgrade -y
```
```
sudo apt full-upgrade
```
- On receiving a prompt for Postfix Configuration, select No configuration and proceed.
- On receiving a prompt for PAM Configuration, select No and proceed.

Configuring the AppViewX Repository

Validate the authentication for the repos.appviewx.com repository using the command below.
```
cat /etc/apt/auth.conf
```

Create a new APT Repository; add the AppViewX repository for Ubuntu 22.04 (Jammy Jellyfish).

sudo vi /etc/apt/sources.list.d/appviewx_repo-jammy.list

Add the following lines to the file:

# AppViewX APT repository
deb https://repos.appviewx.com/repository/ubuntu/ jammy main restricted
deb https://repos.appviewx.com/repository/ubuntu/ jammy-updates main restricted
deb https://repos.appviewx.com/repository/ubuntu/ jammy universe
deb https://repos.appviewx.com/repository/ubuntu/ jammy-updates universe
deb https://repos.appviewx.com/repository/ubuntu/ jammy multiverse
deb https://repos.appviewx.com/repository/ubuntu/ jammy-updates multiverse
deb https://repos.appviewx.com/repository/ubuntu/ jammy-backports main restricted universe multiverse
deb https://repos.appviewx.com/repository/ubuntu/ jammy-security main restricted
deb https://repos.appviewx.com/repository/ubuntu/ jammy-security universe
deb https://repos.appviewx.com/repository/ubuntu/ jammy-security multiverse

Handling Deprecated Modules

To avoid issues with deprecated pam_tally and pam_tally2 modules, replace them with pam_faillock using the following commands:

cd /etc/pam.d

sudo sed -i 's/pam_tally2\?/pam_faillock/g' /etc/pam.d/*