MicroCeph architecture

MicroCeph packages core Ceph daemons (MON, MGR, OSD, and optionally RGW, MDS) into a single snap. These daemons are managed by the microcephd service, which uses a distributed dqlite database for configuration and state. Management is primarily done via the microceph command-line tool interacting with microcephd, alongside standard snapd services.

../../../_images/microceph-cluster.png

MicroCeph Architecture Overview

Components

  • Host System: The underlying Linux operating system where the MicroCeph snap is installed.

  • MicroCeph Snap: The package containing Ceph daemons, microcephd, and management logic. It runs with confinement provided by snapd. See the snap security confinement documentation to learn more about snap security and isolation.

  • microcephd: The core service (based on Microcluster) responsible for managing the MicroCeph cluster state, coordinating actions across nodes (if clustered), and managing the Ceph daemons within the snap.

  • dqlite Database: A distributed SQLite database used by microcephd to store cluster configuration, node status, and other metadata.

  • microceph CLI: The primary tool used by administrators to interact with microcephd for managing MicroCeph instances.

  • Ceph Daemons (within the snap):

    • ceph-mon: Ceph Monitor (MON) daemon(s), maintaining cluster state and consensus.

    • ceph-mgr: Ceph Manager (MGR) daemon(s), providing access to management APIs and modules like the Dashboard.

    • ceph-osd: Ceph object storage daemons (OSDs), managing data on underlying storage devices.

    • ceph-radosgw (optional): Ceph Object Gateway (RGW) service, providing S3/Swift-compatible object storage.

    • ceph-mds (optional): Metadata Server (MDS) daemons for CephFS.

  • Client Workloads: Consume Ceph storage via RBD block devices, RGW object buckets, or CephFS shared filesystems.