pve-storage-rbd.adoc

Ceph RADOS Block Devices (RBD)

Storage pool type: rbd

Ceph is a distributed object store and file system designed to provide excellent performance, reliability and scalability. RADOS block devices implement a feature rich block level storage, and you get the following advantages:

• thin provisioning

• resizable volumes

• distributed and redundant (striped over multiple OSDs)

• full snapshot and clone capabilities

• self healing

• no single point of failure

• scalable to the exabyte level

• kernel and unser space implementation available

Note	For smaller deployments, it is also possible to run Ceph services directly on your {pve} nodes. Recent hardware has plenty of CPU power and RAM, so running storage services and VMs on same node is possible.

Configuration

This backend supports the common storage properties nodes, disable, content, and the following rbd specific properties:

monhost

List of monitor daemon IPs.

pool

Ceph pool name.

username

RBD user Id.

krbd

Access rbd through krbd kernel module. This is required if you want to use the storage for containers.

Configuration Example ('/etc/pve/storage.cfg')

rbd: ceph3
        monhost 10.1.1.20 10.1.1.21 10.1.1.22
        pool ceph3
        content images
        username admin

Tip	You can use the 'rbd' utility to do low-level management tasks.

Authentication

If you use cephx authentication, you need to copy the keyfile from Ceph to Proxmox VE host.

Create the directory '/etc/pve/priv/ceph' with

mkdir /etc/pve/priv/ceph

Then copy the keyring

scp <cephserver>:/etc/ceph/ceph.client.admin.keyring /etc/pve/priv/ceph/<STORAGE_ID>.keyring

The keyring must be named to match your <STORAGE_ID>. Copying the keyring generally requires root privileges.

Storage Features

The rbd backend is a block level storage, and implements full snapshot and clone functionality.

Table 1. Storage features for backend rbd

Content types	Image formats	Shared	Snapshots	Clones
images rootdir	raw	yes	yes	yes