Create a configuration
In this step you will create a configuration file that c4 will use when deploying Exasol on the hosts. The configuration file defines all necessary parameters such as host addresses, storage devices (disks), the number of nodes, passwords, etc.
Create configuration file
On the host that will be used to run the installation, create a file with the filename config
in the same directory as the c4 binary. For example, if you are using the nano text editor:
nano ./configThe configuration file should define the following parameters:
| Parameter | Data type | Default | Description |
|---|---|---|---|
CCC_HOST_ADDRS
|
string | [empty] |
The IP addresses of the database hosts on the private network, separated by spaces. The number of addresses in this parameter determines the number of nodes that will be installed. |
CCC_HOST_EXTERNAL_ADDRS
|
string | [empty] |
Public IP addresses of the database hosts, separated by spaces. |
CCC_HOST_DATADISK
|
string | [empty] |
Comma-separated list of block devices to be used for the data volume. If block devices are not specified in this parameter, limited file-based storage is used. To find the names of the available block devices on the host, use the command The devices used should have persistent block device names. Exasol recommends using volume management with LVM2. See also System Requirements. |
CCC_HOST_IMAGE_USER
|
string | [empty] |
Username that will be used to log in to the SSH instances. The user must have sudo privileges on the instances. |
CCC_HOST_IMAGE_PASSWORD
|
string | [empty] |
Password for the user if required for sudo. The password is passed in plaintext to the instances. |
CCC_HOST_KEY_PAIR_FILE
|
string | [empty] | Name of the file that contains the private SSH key required to access host instances. |
CCC_PLAY_WORKING_COPY
|
string | [empty] |
Specifies the Exasol package to install, using the format For example: |
CCC_PLAY_DB_PASSWORD
|
string | aX1234567
|
Password for the database sys user. |
CCC_PLAY_ROOTLESS
|
boolean | false |
Use rootless deployment mode (OPTIONAL). Rootless installation requires additional system configuration. For more information, see Rootless Installation. |
CCC_PLAY_ADMIN_PASSWORD
|
string | aX1234567
|
Password for the system administration user admin in COS. |
CCC_PLAY_RESERVE_NODES (optional) |
integer |
[empty] |
The number of hosts to use as reserve nodes. Reserve nodes are inactive nodes that can automatically take over from an active node in case of failure. For more information about the failover mechanism, see Fail Safety (On-Prem). The reserve nodes are part of the total number of nodes. For example, deploying with 4 nodes and |
The username for the installation user can be any name allowed by the operating system. In the following examples, the user has the username exasol
.
Example configuration
The following configuration file will result in a deployment with 3 database nodes and one reserve node.
CCC_HOST_ADDRS="10.0.0.11 10.0.0.12 10.0.0.13 10.0.0.14"
CCC_HOST_EXTERNAL_ADDRS="203.0.113.11 203.0.113.12 203.0.113.13 203.0.113.14"
CCC_HOST_DATADISK=/dev/mapper/exasol_disk_1,/dev/mapper/exasol_disk_2
CCC_HOST_IMAGE_USER=exasol
CCC_HOST_IMAGE_PASSWORD=exasol123
CCC_HOST_KEY_PAIR_FILE=id_rsa
CCC_PLAY_WORKING_COPY=@exasol-8.32.0
CCC_PLAY_DB_PASSWORD=exasol456
CCC_PLAY_RESERVE_NODES=1Always replace the default passwords by setting unique, secure passwords in your configuration file. Never use the passwords that are used in the examples in this documentation.
Run diagnostic tool (optional)
Before you start the installation you can run a diagnostic tool on your configuration. By using this tool you can detect issues before starting the installation. The diagnostic tool will check things like ssh accessibility to the hosts, sudo password correctness (if the CCC_HOST_IMAGE_PASSWORD parameter is set), missing required parameters, etc.
To run the diagnostic tool, use c4 host diag -i <path to configuration>. For example:
./c4 host diag -i /path_to_config_file/myconfig
OK check_disks
OK check_external_dependencies
OK check_internal_dependencies
OK check_required_params
OK check_sudoFor more information about the diagnostic tool, use c4 host diag --help.
