Manage volumes

Manage volumes

The default OpenStack Block Storage service implementation is an iSCSI solution that uses Logical Volume Manager (LVM) for Linux.


The OpenStack Block Storage service is not a shared storage solution like a Network Attached Storage (NAS) of NFS volumes where you can attach a volume to multiple servers. With the OpenStack Block Storage service, you can attach a volume to only one instance at a time.

The OpenStack Block Storage service also provides drivers that enable you to use several vendors’ back-end storage devices in addition to the base LVM implementation. These storage devices can also be used instead of the base LVM installation.

This high-level procedure shows you how to create and attach a volume to a server instance.

To create and attach a volume to an instance

  1. Configure the OpenStack Compute and the OpenStack Block Storage services through the /etc/cinder/cinder.conf file.
  2. Use the openstack volume create command to create a volume. This command creates an LV into the volume group (VG) cinder-volumes.
  3. Use the openstack server add volume command to attach the volume to an instance. This command creates a unique IQN that is exposed to the compute node.
    • The compute node, which runs the instance, now has an active iSCSI session and new local storage (usually a /dev/sdX disk).
    • Libvirt uses that local storage as storage for the instance. The instance gets a new disk (usually a /dev/vdX disk).

For this particular walkthrough, one cloud controller runs nova-api, nova-scheduler, nova-objectstore, nova-network and cinder-* services. Two additional compute nodes run nova-compute. The walkthrough uses a custom partitioning scheme that carves out 60 GB of space and labels it as LVM. The network uses the FlatManager and NetworkManager settings for OpenStack Compute.

The network mode does not interfere with OpenStack Block Storage operations, but you must set up networking for Block Storage to work. For details, see Networking.

To set up Compute to use volumes, ensure that Block Storage is installed along with lvm2. This guide describes how to troubleshoot your installation and back up your Compute volumes.

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