Enabling a client application

IBM Storage Ceph provides additional protection for pools to prevent unauthorized types of clients from writing data to the pool. This means that system administrators must expressly enable pools to receive I/O operations from Ceph Block Device, Ceph Object Gateway, Ceph Filesystem or for a custom application.

To enable a client application to conduct I/O operations on a pool, execute the following:

Syntax

ceph osd pool application enable POOL_NAME APP {--yes-i-really-mean-it}

Where APP is:

cephfs for the Ceph Filesystem.
rbd for the Ceph Block Device
rgw for the Ceph Object Gateway

Important: A pool that is not enabled will generate a HEALTH_WARN status.

In that scenario, the output for ceph health detail -f json-pretty gives the following output:

{
    "checks": {
        "POOL_APP_NOT_ENABLED": {
            "severity": "HEALTH_WARN",
            "summary": {
                "message": "application not enabled on 1 pool(s)"
            },
            "detail": [
                {
                    "message": "application not enabled on pool 'POOL_NAME'"
                },
                {
                    "message": "use 'ceph osd pool application enable POOL_NAME APP', where APP is 'cephfs', 'rbd', 'rgw', or freeform for custom applications."
                }
            ]
        }
    },
    "status": "HEALTH_WARN",
    "overall_status": "HEALTH_WARN",
    "detail": [
        "'ceph health' JSON format has changed in luminous. If you see this your monitoring system is scraping the wrong fields. Disable this with 'mon health preluminous compat warning = false'"
    ]
}

Note:

Specify a different APP value for a custom application.
Initialize pools for the Ceph Block Device with rbd pool init POOL_NAME.