Backing storage

Now that you have seen how to use Cinder, you may be wondering where that volume that was created was stored. The cloud may be a facade of endless resources, but the reality is that there are actual physical resources that have to back the virtual resources of the cloud. By default, Cinder is configured to use LVM as its backing store. In Chapter 1, RDO Installation, Ceph was indicated for configuration. If that had not been done, Triple-O would have created a virtual disk and mounted it as a loopback device on the control node to use as the LVM physical volume to create a cinder-volumes volume group. The Cinder volume you just created would have been a logical volume in the cinder-volumes volume group. This is not an ideal place to store a virtual storage resource for anything more than a demonstration. Using a virtual disk mounted as a loopback device has very poor performance and will quickly become a bottleneck under load.

Cinder types

There are many different types of...