Uninstall Exasol

This article explains how to completely uninstall Exasol 8 from a host system.

Prerequisites

The user performing this procedure must either be root or a user with sudo access.

Procedure

The following examples use the c4 and confd_client command-line tools in a Linux terminal. For more information about these tools, see Exasol Deployment Tool (c4) and ConfD.

Step 1: Shut down the database

Connect to the cluster operating system (COS) using c4 connect -t <DEPLOYMENT>[.<NODE>]/cos. For example:
```
./c4 connect -t 1/cos
```
For more information about how to use c4 connect, see How to use c4.
If the database is running, stop it now using the ConfD job db_stop. For example:
```
confd_client db_stop db_name: MY_DATABASE
```
To verify that the database has stopped, use the ConfD job db_state. If the result is setup, the database is stopped. For example:
```
confd_client db_state db_name: MY_DATABASE
...
Result:
'setup'
```

Step 2: Remove resources on the hosts

This operation is slightly different depending on whether the installation was made by root or by a non-root user (rootless installation).

To remove all resources that were created by c4 on the host system, run the following commands:

If the installation was made by root:

If you are logged in as root, sudo should be omitted in the following commands.

# stop and disable the c4 services
sudo systemctl stop c4_cloud_command
sudo systemctl stop c4
sudo systemctl disable c4
sudo systemctl disable c4_cloud_command

# remove the c4 services
sudo rm /etc/systemd/system/c4_cloud_command.service
sudo rm /etc/systemd/system/c4_cloud_command.env
sudo rm /etc/systemd/system/c4.service
sudo rm /etc/systemd/system/c4.env

# remove directories and files created by c4
sudo rm -r /var/lib/ccc
sudo rm -r /usr/local/bin/c4
sudo rm -r /var/log/ccc

# unmount and remove the /x mount point
sudo umount /x && sudo rm -rf /x

If the installation was made by a non-root user (rootless installation):

# stop and disable the c4 services
systemctl --user stop c4_cloud_command
systemctl --user stop c4
systemctl --user disable c4
systemctl --user disable c4_cloud_command

# remove the c4 services
rm $HOME/.config/systemd/user/c4_cloud_command.service
rm $HOME/.config/systemd/user/c4_cloud_command.env
rm $HOME/.config/systemd/user/c4.service
rm $HOME/.config/systemd/user/c4.env

# remove directories and files created by c4
rm $HOME/.local/bin/c4

Remove the .ccc directory in the home directory of the installation user:

# if you are logged in as the installation user:
sudo rm -r ~/.ccc

# if you are logged in as root:
rm -r /home/<installation_user>/.ccc

Repeat these steps on all hosts where you have installed Exasol 8.

After Exasol has been uninstalled, you can remove the installation user on the hosts if it is no longer needed. In that case you must be logged in as another user with sudo permissions or as root.