ceph-disk – Ceph disk preparation and activation utility for OSD

Synopsis

ceph-disk prepare [–cluster clustername] [–cluster-uuid uuid] [–fs-type xfs|ext4|btrfs] [data-path] [journal-path]

ceph-disk activate [data-path] [–activate-key path] [–mark-init sysvinit|upstart|systemd|auto|none] [–no-start-daemon]

ceph-disk activate-all

ceph-disk list

Description

ceph-disk is a utility that can prepare and activate a disk, partition or directory as a Ceph OSD. It is run directly or triggered by ceph-deploy or udev. It can also be triggered by other deployment utilities like Chef, Juju, Puppet etc.

It actually automates the multiple steps involved in manual creation and start of an OSD into two steps of preparing and activating the OSD by using the subcommands prepare and activate.

Subcommands

prepare

Prepare a directory, disk or drive for a Ceph OSD. It creates a GPT partition, marks the partition with Ceph type uuid, creates a file system, marks the file system as ready for Ceph consumption, uses entire partition and adds a new partition to the journal disk. It is run directly or triggered by ceph-deploy.

Usage:

ceph-disk prepare --cluster [cluster-name] --cluster-uuid [uuid] --fs-type
[ext4|xfs|btrfs] [data-path] [journal-path]

Other options like --osd-uuid, --journal-uuid, --zap-disk, --data-dir, --data-dev, --journal-file, --journal-dev, --dmcrypt and --dmcrypt-key-dir can also be used with the subcommand.

activate

Activate the Ceph OSD. It mounts the volume in a temporary location, allocates an OSD id (if needed), remounts in the correct location /var/lib/ceph/osd/$cluster-$id and starts ceph-osd. It is triggered by udev when it sees the OSD GPT partition type or on ceph service start with ceph disk activate-all. It is also run directly or triggered by ceph-deploy.

Usage:

ceph-disk activate [PATH]

Here, [PATH] is path to a block device or a directory.

An additional option --activate-key has to be used with this subcommand when a copy of /var/lib/ceph/bootstrap-osd/{cluster}.keyring isn’t present in the OSD node.

Usage:

ceph-disk activate [PATH] [--activate-key PATH]

Another option --mark-init can also be used with this subcommand. --mark-init provides init system to manage the OSD directory. It defaults to auto which detects the init system suitable for ceph (either sysvinit, systemd or upstart). The argument can be used to override the init system. It may be convenient when an operating system supports multiple init systems, such as Debian GNU/Linux jessie with systemd and sysvinit. If the argument is none, the OSD is not marked with any init system and ceph-disk activate needs to be called explicitely after each reboot.

Usage:

ceph-disk activate [PATH] [--mark-init *sysvinit|upstart|systemd|auto|none*]

If the option --no-start-daemon is given, the activation steps are performed but the OSD daemon is not started.

activate-journal

Activate an OSD via it’s journal device. udev triggers ceph-disk activate-journal <dev> based on the partition type.

Usage:

ceph-disk activate-journal [DEV]

Here, [DEV] is the path to a journal block device.

Others options like --activate-key and --mark-init can also be used with this subcommand.

--mark-init provides init system to manage the OSD directory.

Usage:

ceph-disk activate-journal [--activate-key PATH] [--mark-init INITSYSTEM] [DEV]

activate-all

Activate all tagged OSD partitions. activate-all relies on /dev/disk/by-parttype-uuid/$typeuuid.$uuid to find all partitions. Special udev rules are installed to create these links. It is triggered on ceph service start or run directly.

Usage:

ceph-disk activate-all

Others options like --activate-key and --mark-init can also be used with this subcommand.

--mark-init provides init system to manage the OSD directory.

Usage:

ceph-disk activate-all [--activate-key PATH] [--mark-init INITSYSTEM]

list

List disk partitions and Ceph OSDs. It is run directly or triggered by ceph-deploy.

Usage:

ceph-disk list

suppress-activate

Suppress activate on a device (prefix). Mark devices that you don’t want to activate with a file like /var/lib/ceph/tmp/suppress-activate.sdb where the last bit is the sanitized device name (/dev/X without the /dev/ prefix). A function is_suppressed() checks for and matches a prefix (/dev/). It means suppressing sdb will stop activate on sdb1, sdb2, etc.

Usage:

ceph-disk suppress-activate [PATH]

Here, [PATH] is path to a block device or a directory.

unsuppress-activate

Stop suppressing activate on a device (prefix). It is used to activate a device that was earlier kept deactivated using suppress-activate.

Usage:

ceph-disk unsuppress-activate [PATH]

Here, [PATH] is path to a block device or a directory.

zap

Zap/erase/destroy a device’s partition table and contents. It actually uses sgdisk and it’s option --zap-all to destroy both GPT and MBR data structures so that the disk becomes suitable for repartitioning. sgdisk then uses --mbrtogpt to convert the MBR or BSD disklabel disk to a GPT disk. The prepare subcommand can now be executed which will create a new GPT partition. It is also run directly or triggered by ceph-deploy.

Usage:

ceph-disk zap [DEV]

Here, [DEV] is path to a block device.

Options

--prepend-to-path PATH

Prepend PATH to $PATH for backward compatibility (default /usr/bin).

--statedir PATH

Directory in which ceph configuration is preserved (default /usr/lib/ceph).

--sysconfdir PATH

Directory in which ceph configuration files are found (default /etc/ceph).

--cluster

Provide name of the ceph cluster in which the OSD is being prepared.

--cluster-uuid

Provide uuid of the ceph cluster in which the OSD is being prepared.

--fs-type

Provide the filesytem type for the OSD. e.g. xfs/ext4/btrfs.

--osd-uuid

Unique OSD uuid to assign to the disk.

--journal-uuid

Unique uuid to assign to the journal.

--zap-disk

Destroy the partition table and content of a disk.

--data-dir

Verify that [data-path] is of a directory.

--data-dev

Verify that [data-path] is of a block device.

--journal-file

Verify that journal is a file.

--journal-dev

Verify that journal is a block device.

--dmcrypt

Encrypt [data-path] and/or journal devices with dm-crypt.

--dmcrypt-key-dir

Directory where dm-crypt keys are stored.

--activate-key

Use when a copy of /var/lib/ceph/bootstrap-osd/{cluster}.keyring isn’t present in the OSD node. Suffix the option by the path to the keyring.

--mark-init

Provide init system to manage the OSD directory.

Availability

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

See also

ceph-osd(8), ceph-deploy(8)