Ceph
Ceph is a storage platform with a focus on being distributed, resilient, and having good performance and high reliability. Ceph can also be used as a block storage solution for virtual machines or through the use of FUSE, a conventional filesystem. Ceph is extremely configurable, with administrators being able to control virtually all aspects of the system. A command line interface is used to monitor and control the cluster. The platform also contains authentication & authorization features, and various gateways to make it compatible with systems such as OpenStack Swift and Amazon S3.
From Wikipedia: Ceph (software):
- Ceph is a free software storage platform designed to present object, block, and file storage from a single distributed computer cluster. Ceph's main goals are to be completely distributed without a single point of failure, scalable to the exabyte level, and freely-available. The data is replicated, making it fault tolerant.
From Ceph.com:
- Ceph is a distributed object store and file system designed to provide excellent performance, reliability and scalability.
The official documentation states "the manual procedure is primarily for exemplary purposes for those developing deployment scripts with Chef, Juju, Puppet, etc.".
Terminology
- Client : Something which connects to a Ceph cluster to access data but is not part of the Ceph cluster itself.
- MONs : Also known as monitors, these store cluster state and maps containing information about the cluster such as running services and data locations.
- MDSs : Also known as metadata servers, these store metadata for the Ceph filesystem to reduce load on the storage cluster (e.g. information for commands such as
ls
). - Node : A machine which is running Ceph services, such as OSDs or MONs.
- OSDs : Also known as OSD daemons, these are responsible for the storage of data within the cluster and also conduct various related operations such as replication, recovery, and rebalancing.
- Storage cluster : The core set of software responsible for storing data (OSDs+MONs).
Installation
Packages
Install it with the package cephAUR. You may instead install ceph-gitAUR if you want a bleeding-edge installation.
Install cephAUR on all nodes that will be in the cluster.
NTP Client
Install and run a time synchronisation client on the node. See Time synchronization for details.
Bootstrapping a storage cluster
Before a storage cluster can operate, the monitors for that cluster must be bootstrapped with several identifiers and keyrings.
The upstream Ceph documentation is well-written and kept updated with the latest releases.
To boostrap a storage cluster, follow the steps documented in the official manual deployment guide.
Starting a monitor
Since your system most likely uses systemd, you can enable a monitor as a systemd unit.
As an example, for a monitor named node1
start and enable as detailed in Systemd#Using units.
See also
- Official site
- Official source code