ClickHouse/dbms/tests/integration/test_multiple_disks/configs/config.d/storage_configuration.xml

<yandex>

<storage_configuration>
    <disks>
        <!--default> <! - - path for default disk is provided in main config - - >
            <keep_free_space_bytes>0</keep_free_space_bytes>
        </default-->
        <mainstorage>
            <path>/mainstorage/</path><!-- trailing slash is mandatory -->
            <keep_free_space_bytes>1000000</keep_free_space_bytes>
        </mainstorage>
        <jbod1>
            <path>/jbod1/</path>
            <keep_free_space_bytes>10000000</keep_free_space_bytes>
        </jbod1>
        <jbod2>
            <path>/jbod2/</path>
            <keep_free_space_bytes>10000000</keep_free_space_bytes>
        </jbod2>
        <external>
            <path>/external/</path>
            <keep_free_space_bytes>10000000</keep_free_space_bytes>
        </external>
    </disks>

    <policies>
        <!-- default: store on mainstorage -->
        <default>
            <volume>
                <disk>mainstorage</disk>
                <max_data_part_size_bytes>20000000</max_data_part_size_bytes>
            </volume>
        </default>

        <!-- store local by default, store big parts on external -->
        <default_disk_with_external>
            <volume>
                <!-- names for the volumes should be added to allow moving parts between volumed with DDL commands -->
                <disk>default</disk>
                <max_data_part_size_bytes>2000000</max_data_part_size_bytes>
            </volume>
            <volume>
                <disk>external</disk>
                <max_data_part_size_bytes>20000000</max_data_part_size_bytes>
            </volume>
        </default_disk_with_external>

        <!-- store on JBOD by default (round-robin), store big parts on external -->
        <jbod_with_external>
            <volume>
                <disk>jbod1</disk>
                <disk>jbod2</disk>
                <max_data_part_size_bytes>10000000</max_data_part_size_bytes>
                <!-- max_data_part_size_ratio>0.2</max_data_part_size_ratio -->
            </volume>
            <volume>
                <disk>external</disk>
                <!--max_data_part_size_bytes>30000000</max_data_part_size_bytes-->
            </volume>
        </jbod_with_external>

        <mainstorage_only>
            <volume>
                <disk>mainstorage</disk>
                <max_data_part_size_bytes>9000000</max_data_part_size_bytes>
            </volume>
            <volume>
                <disk>external</disk>
                <max_data_part_size_bytes>20000000</max_data_part_size_bytes>
            </volume>
       </mainstorage_only>


    </policies>

</storage_configuration>

</yandex>