Ceph

1. Ceph
2. Reliable autonomous distributed object store (RADOS)
   1. RADOS gateway (RGW)
   2. RADOS block device (RBD)
   3. CephFS

• distributed FS based on object file system – RADOS
• provides object, block, file abstractions

Reliable autonomous distributed object store (RADOS)

• elements
  • object store daemon (OSD): P2P connection between daemons
  • FS: xfs, ext4, btrfs
  • disk: disks or RAID groups
• OSD per disk in lieu of controller
• monitor: vote whether node is alive
• controlled replication under scalable hashing (CRUSH): hash to determine which OSD has data

RADOS gateway (RGW)

• web

RADOS block device (RBD)

• blocks → 4 MB objects
• supports replication, snapshot, CoW clones

CephFS

• file service