Libro sobre Proxmox maestria
High Availability Storage for High Availability Cluster
Controlled Replication Under Scalable Hashing (CRUSH) is an algorithm used in Ceph to store and retrieve data by computing data storage locations within the cluster. It does so by providing a per-device weight value to distribute data objects among storage devices. The value is autoassigned based on the actual size of the disk drive being used. For example, a 2 TB disk drive may have the approximate weight of 1.81. The drive will keep writing data until it reaches this weight. By design, CRUSH distributes data evenly across weighted devices to maintain a balanced utilization of storage and device bandwidth resources. A user can customize a CRUSH map to fit any cluster environment of any size.
Monitor
For more details on CRUSH maps, visit http://ceph.com/docs/ master/rados/operations/crush-map/.
A Ceph Monitor (MON) is a cluster monitor daemon node that holds the OSD map, PG map, CRUSH map, and Monitor map. Monitors can be set up on the same server node with OSDs or on a fully separated machine. For a stable Ceph cluster, setting up separate nodes with Monitors is highly recommended. Since Monitors only keep track of everything that happens within the cluster and not the actual read/ write process of cluster data, the Monitor node can be very underpowered, and thus less expensive. To achieve a healthy status of the Ceph cluster, a minimum of three monitors is needed to be set up. A healthy status is when every status in the cluster is OK, without any warnings or errors. Note that with the recent integration of Ceph with Proxmox, the same Proxmox node can be used as a Monitor. Starting from Proxmox 3.2, it is possible to set up Ceph Monitors on the same Proxmox node, thus eliminating the need to use a separate node for Monitors. Monitors can also be managed using the Proxmox GUI.
For details on Ceph Monitor, visit http://ceph.com/docs/ master/man/8/ceph-mon/.