# Block Storage (RBD)

Ceph RBD (RADOS Block Device) provides thin-provisioned, replicated block devices backed by your cluster. RBD volumes suit virtual machine disks, databases, and Kubernetes persistent volumes.

## Typical workflow

Create a pool and an image, then map it on a client. Run these from an admin host with access to the cluster:

```bash
ceph osd pool create rbd-pool
rbd create rbd-pool/vol01 --size 100G
rbd map rbd-pool/vol01
mkfs.ext4 /dev/rbd0
mount /dev/rbd0 /mnt/vol01
```

## Use with platforms

- Virtual machines. Attach RBD images as VM disks.
- Kubernetes. Use the [Ceph CSI](https://github.com/ceph/ceph-csi) driver to provision RBD persistent volumes dynamically.
- Databases. Back high-I/O databases with an NVMe pool. See [Performance & Tiering](https://docs.zcp.zsoftly.ca/cloud-storage/reference/performance-tiering).

| Resource | URL |
| --- | --- |
| Ceph RBD (Block Storage) | [https://docs.ceph.com/en/latest/rbd/](https://docs.ceph.com/en/latest/rbd/) |
| Ceph CSI | [https://github.com/ceph/ceph-csi](https://github.com/ceph/ceph-csi) |

You mirror RBD images to another cluster for disaster recovery. See [Replication & DR](https://docs.zcp.zsoftly.ca/cloud-storage/reference/replication-dr).