Volume Specifications
In OpenStack, “volumes” are persistent storage that you can attach to your running OpenStack Compute instances to. In openstack we have set up three classes of service for volumes. These have different limits, which are detailed below.
Volume Types
We have two main volume types:
- high-iops
- standard
Volume Type List
An overview of the two volume types below:
| Name | Read Bytes Sec | Read IOPS Sec | Write Bytes Sec | Write IOPS Sec |
|---|---|---|---|---|
| high-iops | 524288000 | 10000 | 524288000 | 10000 |
| standard | 209715200 | 2500 | 209715200 | 2500 |
Choosing a Volume Type
You can select one of the two volume types upon creation of a volume with the following command (Unless otherwise specified, the type “default” is always used): $ openstack volume create <volume-name> --size 10 --type high-iops
Changing the Volume Type
You can adjust the selected type of a volume. To do so, you can use the “Change Volume Type” function in the dashboard. Alternatively, you can change the type via the CLI with the following command: $ openstack volume set <volume-name> --type high-iops However, changing the volume type is only possible if the volume is not currently in use by an instance.
Volume Group Specifications
In OpenStack, “Volume Groups” provide a way to logically group multiple volumes. This simplifies management (e.g., creating snapshots for all volumes in a group) and helps organize complex application environments.
Volume Group Type List
We currently provide the following volume group type:
| Name | Description | Consistency Support | Public |
|---|---|---|---|
| standard_group | Standard grouping for related volumes. | No | Yes |
NOTE: The
standard_grouptype serves as a logical container. However, it does not support cross-volume consistency (Consistency Groups). Snapshots are taken sequentially.
Using Volume Groups
1. Creating a Volume Group
To create a new group, you must specify the standard_group type:
openstack volume group create --type standard_group <group-name>
2. Adding Volumes to a Group
A volume can be assigned to a group during its creation:
openstack volume create --size 10 --group <group-name> <volume-name>
3. Creating Group Snapshots
You can initiate a common snapshot point for all volumes within the group:
openstack volume group snapshot create --group <group-name> <snapshot-name>