Ceph is a distributed storage and network file system designed to provide excellent performance, reliability, and scalability.


Ceph is a distributed storage and network file system designed to provide
excellent performance, reliability, and scalability.

This charm deploys a Ceph cluster.


The ceph charm has two pieces of mandatory configuration for which no defaults
are provided. You must set these configuration options before deployment or the charm will not work:

    uuid specific to a ceph cluster used to ensure that different
    clusters don't get mixed up - use `uuid` to generate one.

    a ceph generated key used by the daemons that manage to cluster
    to control security.  You can use the ceph-authtool command to
    generate one:

        ceph-authtool /dev/stdout --name=mon. --gen-key

These two pieces of configuration must NOT be changed post bootstrap; attempting
to do this will cause a reconfiguration error and new service units will not join
the existing ceph cluster.

The charm also supports the specification of storage devices to be used in the
ceph cluster.

    A list of devices that the charm will attempt to detect, initialise and
    activate as ceph storage.

    This can be a superset of the actual storage devices presented to each
    service unit and can be changed post ceph bootstrap using `juju set`.

    The full path of each device must be provided, e.g. /dev/vdb.

    For Ceph >= 0.56.6 (Raring or the Grizzly Cloud Archive) use of
    directories instead of devices is also supported.

At a minimum you must provide a juju config file during initial deployment
with the fsid and monitor-secret options (contents of cepy.yaml below):

    fsid: ecbb8960-0e21-11e2-b495-83a88f44db01
    monitor-secret: AQD1P2xQiKglDhAA4NGUF5j38Mhq56qwz+45wg==
    osd-devices: /dev/vdb /dev/vdc /dev/vdd /dev/vde

Specifying the osd-devices to use is also a good idea.

Boot things up by using:

juju deploy -n 3 --config ceph.yaml ceph

By default the ceph cluster will not bootstrap until 3 service units have been
deployed and started; this is to ensure that a quorum is achieved prior to adding
storage devices.


This charm supports pausing and resuming ceph's health functions on a cluster, for example when doing maintainance on a machine. to pause or resume, call:

juju action do --unit ceph/0 pause-health or juju action do --unit ceph/0 resume-health

Scale Out Usage

You can use the Ceph OSD and Ceph Radosgw charms:

Network Space support

This charm supports the use of Juju Network Spaces, allowing the charm to be bound to network space configurations managed directly by Juju. This is only supported with Juju 2.0 and above.

Network traffic can be bound to specific network spaces using the public (front-side) and cluster (back-side) bindings:

juju deploy ceph --bind "public=data-space cluster=cluster-space"

alternatively these can also be provided as part of a Juju native bundle configuration:

  charm: cs:xenial/ceph
  num_units: 1
    public: data-space
    cluster: cluster-space

Please refer to the Ceph Network Reference for details on how using these options effects network traffic within a Ceph deployment.

NOTE: Spaces must be configured in the underlying provider prior to attempting to use them.

NOTE: Existing deployments using ceph-*-network configuration options will continue to function; these options are preferred over any network space binding provided if set.

Contact Information


Report bugs on Launchpad


Technical Footnotes

This charm uses the new-style Ceph deployment as reverse-engineered from the
Chef cookbook at https://github.com/ceph/ceph-cookbooks, although we selected
a different strategy to form the monitor cluster. Since we don't know the
names or addresses of the machines in advance, we use the relation-joined
hook to wait for all three nodes to come up, and then write their addresses
to ceph.conf in the "mon host" parameter. After we initialize the monitor
cluster a quorum forms quickly, and OSD bringup proceeds.

The osds use so-called "OSD hotplugging". ceph-disk prepare is used to
create the filesystems with a special GPT partition type. udev is set up
to mount such filesystems and start the osd daemons as their storage becomes
visible to the system (or after udevadm trigger).

The Chef cookbook mentioned above performs some extra steps to generate an OSD
bootstrapping key and propagate it to the other nodes in the cluster. Since
all OSDs run on nodes that also run mon, we don't need this and did not
implement it.

See the documentation for more information on Ceph monitor cluster deployment strategies and pitfalls.


                            YAML-formatted associative array of sysctl key/value pairs to be set
persistently. By default we set pid_max, max_map_count and 
threads-max to a high value to avoid problems with large numbers (>20)
of OSDs recovering. very large clusters should set those values even
higher (e.g. max for kernel.pid_max is 4194303).

{ kernel.pid_max : 2097152, vm.max_map_count : 524288, kernel.threads-max: 2097152 }
                            A comma-separated list of nagios servicegroups.
If left empty, the nagios_context will be used as the servicegroup

                            Format of filesystem to use for OSD devices; supported formats include:
  xfs (Default >= 0.48.3)
  ext4 (Only option < 0.48.3)
  btrfs (experimental and not recommended)
Only supported with ceph >= 0.48.3.

                            The IP address and netmask of the cluster (back-side) network (e.g.,
If multiple networks are to be used, a space-delimited list of a.b.c.d/x
can be provided.

                            If set to True, supporting services will log to syslog.

                            Ceph osd journal size. The journal size should be at least twice the
product of the expected drive speed multiplied by filestore max sync
interval. However, the most common practice is to partition the journal
drive (often an SSD), and mount it such that Ceph uses the entire
partition for the journal.
Only supported with ceph >= 0.48.3.

                            Configure use of direct IO for OSD journals.
                            Optional configuration to support use of additional sources such as:

  - ppa:myteam/ppa
  - cloud:trusty-proposed/kilo
  - http://my.archive.com/ubuntu main

The last option should be used in conjunction with the key configuration

Note that a minimum ceph version of 0.48.2 is required for use with this
charm which is NOT provided by the packages in the main Ubuntu archive
for precise but is provided in the Ubuntu cloud archive.

                            The devices to format and set up as osd volumes.
These devices are the range of devices that will be checked for and
used across all service units, in addition to any volumes attached
via the --storage flag during deployment.
For ceph >= 0.56.6 these can also be directories instead of devices - the
charm assumes anything not starting with /dev is a directory instead.

                            If True enables IPv6 support. The charm will expect network interfaces
to be configured with an IPv6 address. If set to False (default) IPv4
is expected.

NOTE: these charms do not currently support IPv6 privacy extension. In
order for this charm to function correctly, the privacy extension must be
disabled and a non-temporary address must be configured/available on
your network interface.

                            Which authentication flavour to use.
Valid options are "cephx" and "none".  If "none" is specified,
keys will still be created and deployed so that it can be
enabled later.

                            This value will become the mon. key. To generate a suitable value use:
  ceph-authtool /dev/stdout --name=mon. --gen-key
This configuration element is mandatory and the service will fail on
install if it is not provided.

                            The IP address and netmask of the public (front-side) network (e.g.,
If multiple networks are to be used, a space-delimited list of a.b.c.d/x
can be provided.

                            By default, the charm will raise errors if a whitelisted device is found,
but for some reason the charm is unable to initialize the device for use
by Ceph.
Setting this option to 'True' will result in the charm classifying such
problems as warnings only and will not result in a hook error.

                            Key ID to import to the apt keyring to support use with arbitary source
configuration from outside of Launchpad archives or PPA's.

                            User provided Ceph configuration. Supports a string representation of
a python dictionary where each top-level key represents a section in
the ceph.conf template. You may only use sections supported in the
WARNING: this is not the recommended way to configure the underlying
services that this charm installs and is used at the user's own risk.
This option is mainly provided as a stop-gap for users that either
want to test the effect of modifying some config or who have found
a critical bug in the way the charm has configured their services
and need it fixed immediately. We ask that whenever this is used,
that the user consider opening a bug on this charm at
http://bugs.launchpad.net/charms providing an explanation of why the
config was needed so that we may consider it for inclusion as a
natively supported config in the the charm.

                            fsid of the ceph cluster. To generate a suitable value use `uuid`
This configuration element is mandatory and the service will fail on
install if it is not provided.

                            The device to use as a shared journal drive for all OSD's.  By default
no journal device will be used.
Only supported with ceph >= 0.48.3.

                            Mon and OSD debug level. Max is 20.
                            Used by the nrpe-external-master subordinate charm.
A string that will be prepended to instance name to set the host name
in nagios. So for instance the hostname would be something like:
If you're running multiple environments with the same services in them
this allows you to differentiate between them.

                            By default, the charm will not re-format a device that already looks
as if it might be an OSD device.  This is a safeguard to try to
prevent data loss.
Specifying this option (any value) forces a reformat of any OSD devices
found which are not already mounted.

                            Apply system hardening. Supports a space-delimited list of modules
to run. Supported modules currently include os, ssh, apache and mysql.

                            How many nodes to wait for before trying to create the monitor cluster
this number needs to be odd, and more than three is a waste except for
very large clusters.

                            Cloud instances provider ephermeral storage which is normally mounted
on /mnt.
Providing this option will force an unmount of the ephemeral device
so that it can be used as a OSD storage device.  This is useful for
testing purposes (cloud deployment is not a typical use case).