ceph-volume – Ceph OSD deployment tool

Synopsis

ceph-volume [-h] [–cluster CLUSTER] [–log-level LOG_LEVEL]
[–log-path LOG_PATH]
ceph-volume lvm [ trigger | create | activate | prepare ]

Description

ceph-volume is a single purpose command line tool to deploy logical volumes as OSDs, trying to maintain a similar API to ceph-disk when preparing, activating, and creating OSDs.

It deviates from ceph-disk by not interacting or relying on the udev rules that come installed for Ceph. These rules allow automatic detection of previously setup devices that are in turn fed into ceph-disk to activate them.

Commands

lvm

By making use of LVM tags, the lvm sub-command is able to store and later re-discover and query devices associated with OSDs so that they can later activated.

Subcommands:

activate Enables a systemd unit that persists the OSD ID and its UUID (also called fsid in Ceph CLI tools), so that at boot time it can understand what OSD is enabled and needs to be mounted.

Usage:

ceph-volume lvm activate --filestore <osd id> <osd fsid>

Optional Arguments:

  • [-h, –help] show the help message and exit
  • [–bluestore] filestore objectstore (not yet implemented)
  • [–filestore] filestore objectstore (current default)

prepare Prepares a logical volume to be used as an OSD and journal using a filestore setup (bluestore support is planned). It will not create or modify the logical volumes except for adding extra metadata.

Usage:

ceph-volume lvm prepare --filestore --data <data lv> --journal <journal device>

Optional arguments:

  • [-h, –help] show the help message and exit
  • [–journal JOURNAL] A logical group name, path to a logical volume, or path to a device
  • [–journal-size GB] Size (in GB) A logical group name or a path to a logical volume
  • [–bluestore] Use the bluestore objectstore (not currently supported)
  • [–filestore] Use the filestore objectstore (currently the only supported object store)
  • [–osd-id OSD_ID] Reuse an existing OSD id
  • [–osd-fsid OSD_FSID] Reuse an existing OSD fsid

Required arguments:

  • --data

    A logical group name or a path to a logical volume

create Wraps the two-step process to provision a new osd (calling prepare first and then activate) into a single one. The reason to prefer prepare and then activate is to gradually introduce new OSDs into a cluster, and avoiding large amounts of data being rebalanced.

The single-call process unifies exactly what prepare and activate do, with the convenience of doing it all at once. Flags and general usage are equivalent to those of the prepare subcommand.

trigger This subcommand is not meant to be used directly, and it is used by systemd so that it proxies input to ceph-volume lvm activate by parsing the input from systemd, detecting the UUID and ID associated with an OSD.

Usage:

ceph-volume lvm trigger <SYSTEMD-DATA>

The systemd “data” is expected to be in the format of:

<OSD ID>-<OSD UUID>

The lvs associated with the OSD need to have been prepared previously, so that all needed tags and metadata exist.

Positional arguments:

  • <SYSTEMD_DATA> Data from a systemd unit containing ID and UUID of the OSD.

Availability

ceph-volume is part of Ceph, a massively scalable, open-source, distributed storage system. Please refer to the documentation at http://docs.ceph.com/ for more information.

See also

ceph-osd(8), ceph-disk(8),