openstack-manuals/doc/admin-guide/source/blockstorage-manage-volumes.rst

Manage volumes

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

Note

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 cinder.conf file.
2. Use the cinder create command to create a volume. This command creates an LV into the volume group (VG) cinder-volumes.
3. Use the nova volume-attach 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.

blockstorage-boot-from-volume.rst blockstorage_nfs_backend.rst blockstorage_glusterfs_backend.rst blockstorage_multi_backend.rst blockstorage_backup_disks.rst blockstorage_volume_migration.rst blockstorage_glusterfs_removal.rst blockstorage_volume_backups.rst blockstorage_volume_backups_export_import.rst blockstorage-lio-iscsi-support.rst blockstorage_volume_number_weigher.rst blockstorage-consistency-groups.rst blockstorage-driver-filter-weighing.rst blockstorage_ratelimit_volume_copy_bandwidth.rst blockstorage_over_subscription.rst blockstorage_image_volume_cache.rst blockstorage_volume_backed_image.rst blockstorage_get_capabilities.rst