Manages disks in MicroCeph.


microceph disk [flags]
microceph disk [command]

Available commands:

add         Add a Ceph disk (OSD)
list        List servers in the cluster
remove      Remove a Ceph disk (OSD)

Global flags:

-d, --debug       Show all debug messages
-h, --help        Print help
    --state-dir   Path to store state information
-v, --verbose     Show all information messages
    --version     Print version number


Adds one or more new Ceph disks (OSDs) to the cluster, alongside optional devices for write-ahead logging and database management. The command takes arguments which is either one or more paths to block devices such as /dev/sdb, or a specification for loop files.

For block devices, add a space separated list of paths, e.g. “/dev/sda /dev/sdb …”. You may also add WAL and DB devices, but doing this is mutually exclusive with adding more than one OSD block device at a time.

The specification for loop files is of the form loop,<size>,<nr>

size is an integer with M, G, or T suffixes for megabytes, gigabytes, or terabytes. nr is the number of file-backed loop OSDs to create. For instance, a spec of loop,8G,3 will create 3 file-backed OSDs, 8GB each.

Note that loop files can’t be used with encryption nor WAL/DB devices.


microceph disk add <spec> [flags]


--all-available       add all available devices as OSDs
--db-device string    The device used for the DB
--db-encrypt          Encrypt the DB device prior to use
--db-wipe             Wipe the DB device prior to use
--encrypt             Encrypt the disk prior to use (only block devices)
--wal-device string   The device used for WAL
--wal-encrypt         Encrypt the WAL device prior to use
--wal-wipe            Wipe the WAL device prior to use
--wipe                Wipe the disk prior to use


Only the data device is mandatory. The WAL and DB devices can improve performance by delegating the management of some subsystems to additional block devices. The WAL block device stores the internal journal whereas the DB one stores metadata. Using either of those should be advantageous as long as they are faster than the data device. WAL should take priority over DB if there isn’t enough storage for both.

WAL and DB devices can only be used with data devices that reside on a block device, not with loop files. Loop files do not support encryption.


List servers in the cluster


microceph disk list [flags]


Removes a single disk from the cluster.


microceph disk remove <osd-id> [flags]


--bypass-safety-checks               Bypass safety checks
--confirm-failure-domain-downgrade   Confirm failure domain downgrade if required
--timeout int                        Timeout to wait for safe removal (seconds) (default: 300)