Mastering OpenStack - Second Edition

Internal non-shared file storage

In this case, compute nodes can satisfy each instance with enough disk space. This has two main advantages:

• Unlike the first approach, heavy I/O won't affect other instances running in different compute nodes
• Performance increase due to direct access to the disk I/O

However, some further disadvantages can be seen, such as the following:

• Inability to scale when additional storage is needed
• Difficulties in migrating instances from one compute node to another
• Failure of compute nodes automatically leading to instance loss

In all cases, we might have more concerns for reliability and scalability. Thus, adopting the external shared file storage would be more convenient for our OpenStack deployment. Although ...