A volume in OpenStack is a block of storage space (a kind of virtual hard drive) that can be attached to an OpenStack instance. Volumes provide durable and non-volatile storage: This means that the data is retained even if the instance to which the volume is attached is powered off or deleted.
How does an OpenStack volume differ from local disk storage?
When creating an instance, you can choose whether or not to attach a volume to the instance. If you choose not to attach a volume, you will use the instance's 'local disk'. If you choose to use a volume, the local disk is not used, and a new volume is created instead. Unlike a local disk, volumes can be dynamically attached or detached from the instance to which they are connected.
This is also the direct advantage of OpenStack volumes. OpenStack volumes offer extra flexibility and security. They can be easily moved between instances, help with backup creation, and are ideal for data that needs to be stored regularly, such as databases and user data.
Can OpenStack volumes be increased or decreased in size?
A volume can be increased but not decreased in size. This is because we do not have insight into where on the disk the data is stored and which parts of the volume are still empty. When decreasing a volume, there is a very high chance that data will be lost.
What types of volumes are there within OpenStack?
Within OpenStack at TransIP, the volume types stem from two different types of storage platforms. These two storage platforms are CEPH and NetApp.
CEPH is considered suitable for applications where exceptionally high read and write speeds from your storage are not required, while NetApp volumes are better suited for applications that require high disk performance. The main difference between these storage types and their corresponding volumes is the maximum read and write speed, also known as IOPS. On this page, you can see the price differences between these types of volumes.
Both storage platforms can continue to be used alongside each other. One platform does not replace the other. You can also create volumes from both storage platforms on the TransIP OpenStack platforms AMS and AMS2.
Below is more information about the types of volumes we have. We will start with the new storage platform NetApp.
NetApp volumes:
NetApp volumes, also known as ‘Performance volumes’. These volumes have a maximum of 6000 IOPS. They are particularly ideal for users who need fast and efficient storage for demanding applications. These volumes are ‘highly available’ thanks to advanced ‘Raid settings’ on the NetApp machines. The security of NetApp storage is also top-notch.
CEPH volumes:
These volumes are ideal for common applications such as website or application hosting, based on CEPH. You can choose from SSD, NVMe, and Archive and automatically benefit from 3x data storage for optimal redundancy.
Encrypted volumes:
Within AMS2, you can create encrypted volumes. For this, we use ‘Linux Unified Key Setup (LUKS)’. The keys for encryption are automatically generated and securely stored in the Secret Manager.
If you attach an encrypted volume to an instance, the instance retrieves the key from the key manager, Barbican. This feature is exclusive to our CEPH-based volumes.