Overview

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

This charm deploys additional Ceph OSD storage service units and should be used in conjunction with the 'ceph-mon' charm to scale out the amount of storage available in a Ceph cluster.

Usage

The charm also supports specification of the storage devices to use in the ceph cluster::

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

    If the charm detects pre-existing data on a device it will go into a
    blocked state and the operator must resolve the situation utilizing the
    `list-disks`, `zap-disk` and/or `blacklist-*` actions.

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

For example::

ceph-osd:
  options:
    osd-devices: /dev/vdb /dev/vdc /dev/vdd /dev/vde

Example utilizing Juju storage::

ceph-osd:
  storage:
    osd-devices: cinder,20G

Please refer to Juju Storage Documentation for details on support for various storage providers and cloud substrates.

How to deploy::

juju deploy -n 3 ceph-osd
juju deploy ceph-mon --to lxd:0
juju add-unit ceph-mon --to lxd:1
juju add-unit ceph-mon --to lxd:2
juju add-relation ceph-osd ceph-mon

Once the 'ceph-mon' charm has bootstrapped the cluster, it will notify the ceph-osd charm which will scan for the configured storage devices and add them to the pool of available storage.

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-osd --bind "public=data-space cluster=cluster-space"

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

ceph-osd:
  charm: cs:xenial/ceph-osd
  num_units: 1
  bindings:
    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.

AppArmor Profiles

AppArmor is not enforced for Ceph by default. An AppArmor profile can be generated by the charm. However, great care must be taken.

Changing the value of the aa-profile-mode option is disruptive to a running Ceph cluster as all ceph-osd processes must be restarted as part of changing the AppArmor profile enforcement mode.

The generated AppArmor profile currently has a narrow supported use case, and it should always be verified in pre-production against the specific configurations and topologies intended for production.

The AppArmor profile(s) which are generated by the charm should NOT yet be used in the following scenarios:

• When there are separate journal devices.
• On any version of Ceph prior to Luminous.
• On any version of Ubuntu other than 16.04.
• With Bluestore enabled.

Block Device Encryption

The ceph-osd charm supports encryption of underlying block devices supporting OSD's.

To use the 'native' key management approach (where dm-crypt keys are stored in the ceph-mon cluster), simply set the 'osd-encrypt' configuration option::

ceph-osd:
  options:
    osd-encrypt: True

NOTE: This is supported for Ceph Jewel or later.

Alternatively, encryption keys can be stored in Vault; this requires deployment of the vault charm (and associated initialization of vault - see the Vault charm for details) and configuration of the 'osd-encrypt' and 'osd-encrypt-keymanager' options::

ceph-osd:
  options:
    osd-encrypt: True
    osd-encrypt-keymanager: vault

NOTE: This option is only supported with Ceph Luminous or later.

NOTE: Changing these options post deployment will only take effect for any new block devices added to the ceph-osd application; existing OSD devices will not be encrypted.

Contact Information

Author: James Page james.page@ubuntu.com Report bugs at: http://bugs.launchpad.net/charm-ceph-osd/+filebug Location: http://jujucharms.com/ceph-osd