Libro sobre Proxmox maestria
Maps
In Ceph, maps hold information such as a list of participating nodes in a cluster and their locations, data paths, and a list of OSDs with certain data chunks. There are several maps in a Ceph cluster: a cluster map, OSD map for a list of OSDs, monitor map for known monitor nodes, Placement Group (PG) map for the location of objects or data chunks, and a CRUSH map to determine the storage and retrieval of data by computing the data storage location.
A cluster map is a map of devices and buckets that comprise a Ceph cluster. Ceph uses a bucket hierarchy to define nodes or node locations, such as a room, rack, shelf, and host. For example, let's say there are four disk drives used as four OSDs in the following bucket hierarchy:
In the previous example, osd.1 to osd.4 are in the ceph-node-1 rack in rack 22, which is in room 101 inside datacenter dc01. If osd.3 fails, and there is an on-site technician, then an administrator can quickly give the technician the previous bucket hierarchy to identify the exact disk drive location to replace it. There could be hundreds of OSDs in a cluster. A cluster map helps to pin point a single host or disk drive using the bucket hierarchy.