CephFS Quick Start

To use the CephFS Quick Start guide, you must have executed the procedures in the Storage Cluster Quick Start guide first. Execute this quick start on the Admin Host.


  1. Verify that you have an appropriate version of the Linux kernel. See OS Recommendations for details.

    lsb_release -a
    uname -r
  2. On the admin node, use ceph-deploy to install Ceph on your ceph-client node.

    ceph-deploy install ceph-client
  3. Ensure that the Ceph Storage Cluster is running and in an active + clean state. Also, ensure that you have at least one Ceph Metadata Server running.

    ceph -s [-m {monitor-ip-address}] [-k {path/to/ceph.client.admin.keyring}]

Create a Filesystem

You have already created an MDS (Storage Cluster Quick Start) but it will not become active until you create some pools and a filesystem. See Create a Ceph filesystem.

ceph osd pool create cephfs_data <pg_num>
ceph osd pool create cephfs_metadata <pg_num>
ceph fs new <fs_name> cephfs_metadata cephfs_data

Create a Secret File

The Ceph Storage Cluster runs with authentication turned on by default. You should have a file containing the secret key (i.e., not the keyring itself). To obtain the secret key for a particular user, perform the following procedure:

  1. Identify a key for a user within a keyring file. For example:

    cat ceph.client.admin.keyring
  2. Copy the key of the user who will be using the mounted CephFS filesystem. It should look something like this:

       key = AQCj2YpRiAe6CxAA7/ETt7Hcl9IyxyYciVs47w==
  3. Open a text editor.

  4. Paste the key into an empty file. It should look something like this:

  5. Save the file with the user name as an attribute (e.g., admin.secret).

  6. Ensure the file permissions are appropriate for the user, but not visible to other users.

Kernel Driver

Mount CephFS as a kernel driver.

sudo mkdir /mnt/mycephfs
sudo mount -t ceph {ip-address-of-monitor}:6789:/ /mnt/mycephfs

The Ceph Storage Cluster uses authentication by default. Specify a user name and the secretfile you created in the Create a Secret File section. For example:

sudo mount -t ceph /mnt/mycephfs -o name=admin,secretfile=admin.secret


Mount the CephFS filesystem on the admin node, not the server node. See FAQ for details.

Filesystem in User Space (FUSE)

Mount CephFS as a Filesystem in User Space (FUSE).

sudo mkdir ~/mycephfs
sudo ceph-fuse -m {ip-address-of-monitor}:6789 ~/mycephfs

The Ceph Storage Cluster uses authentication by default. Specify a keyring if it is not in the default location (i.e., /etc/ceph):

sudo ceph-fuse -k ./ceph.client.admin.keyring -m ~/mycephfs

Additional Information

See CephFS for additional information. CephFS is not quite as stable as the Ceph Block Device and Ceph Object Storage. See Troubleshooting if you encounter trouble.