Uninstall Exasol

Prerequisites

To perform this procedure you must be logged in as root or as a user with sudo access.

Procedure

Step 1: Shut down the database

1. Connect to the cluster operating system (COS) using c4 connect -i PLAY_ID -s cos.

   Example:
   

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   ./c4 connect -i c3275f84 -s cos

   For more information about how to use c4 connect, see How to use c4.

2. If the database is running, stop it now using the ConfD job db_stop. For example:

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   confd_client db_stop db_name: MY_DATABASE

3. To verify that the database has stopped, use the ConfD job db_state. If the result is setup, the database is stopped.

   Example:
   

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   confd_client db_state db_name: MY_DATABASE
   ...
   Result:
   'setup'

Step 2: Remove resources on the hosts

This part of the procedure is slightly different depending on whether Exasol was installed as root or with a non-root user (rootless installation). For more information, see Rootless Installation.

In Exasol version 2025.1 and later you have to stop the administration UI service (if it is running), then disable and remove it. This step is not relevant for earlier versions of Exasol.

1. To remove all Exasol resources that were created on the host system, run the following commands:

   If Exasol is installed as root:

   If you performing this operation as root, omit sudo in the commands.

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   # stop and disable the c4 services
   sudo systemctl stop c4_cloud_command
   sudo systemctl stop c4
   sudo systemctl disable c4_cloud_command
   sudo systemctl disable c4
   
   # 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
   
   # in Exasol 2025.1 and later, stop/disable the admin ui service and remove it
   sudo systemctl stop exasol-admin-ui
   sudo systemctl disable exasol-admin-ui
   sudo rm /etc/systemd/system/exasol-admin-ui.service
   sudo rm /etc/systemd/system/exasol-admin-ui.env
   
   # remove the 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 Exasol is installed with a non-root user (rootless installation):

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   # 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
   
   # in Exasol 2025.1 and later, stop/disable the admin ui service and remove it
   systemctl --user stop exasol-admin-ui
   systemctl --user disable exasol-admin-ui
   rm $HOME/.config/systemd/user/exasol-admin-ui.service
   rm $HOME/.config/systemd/user/exasol-admin-ui.env
   
   # remove the directories and files created by c4
   rm $HOME/.local/bin/c4

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

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   # 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
   

3. Remove the SSH keys for c4 in the home directory of the installation user:

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   # if you are logged in as the installation user:
   sudo rm -rf ~/.ssh/c4-* 
   
   # if you are logged in as root:
   rm -rf /home/<installation_user>/.ssh/c4-* 

4. Reboot the host to reset all the temporary system parameters.

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

After Exasol has been uninstalled, you can remove the Exasol 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.