Cinder volumes

Our volume service is hosted on the ceph cluster, and delivers add-on disks for the vm's. These volumes are all shaped performance-vise, to prevent single tenants from overloading our ceph cluster. They come in several flavours:

• Slow: The slow volumes are shaped to 50IOPS, which is rather slow. It can be used to simulate very slow disks for instance.
• Normal: This is the general purpose volume type. It is used by most tenants for their general purpose storage needs. It is shaped to 150 IOPS, which corresponds to a fast 10K RPM HDD.
• Fast: If a tenant needs more performance than the Normal type they can request a permission to create a "Fast" volume, which deliveres 300 IOPS.
• VeryFast: Delivering 1K IOPS, the VeryFast volume can give a much greater performance than the other volume types. We should however be careful assigning this volume to our tenants, as it is capable to put some real load onto our ceph cluster if we have multiple of these volumes.

Quotas

The default quotas for cinder volumes are:

eigil@manager:~$ openstack quota show default
+----------------------+---------+
| Field                | Value   |
+----------------------+---------+
    ....
| volumes              | 10      |
| volumes_Fast         | 0       |
| volumes_Normal       | -1      |
| volumes_Slow         | -1      |
| volumes_VeryFast     | 0       |
+----------------------+---------+

Which means that we normally does not allow a tenant to create anything else than Normal and Slow volumes. To give the tenant "eigil" access to create a faster volume one would change this tenants quota:

eigil@manager:~$ openstack quota set eigil --volumes 1 --volume-type Fast

Resulting in changed quotas:

eigil@manager:~$ openstack quota show eigil
+----------------------+----------------------------------+
| Field                | Value                            |
+----------------------+----------------------------------+
   ... 
| volumes              | 10                               |
| volumes_Fast         | 1                                |
| volumes_Normal       | -1                               |
| volumes_Slow         | -1                               |
| volumes_VeryFast     | 0                                |
+----------------------+----------------------------------+