This chapter describes how to configure the OpenStack volume service (openstack-cinder-volume) to use an existing NFS server as an additional back end. In addition, this chapter also describes how to create a volume type that you can use to invoke to create volumes backed by the NFS share.
Prerequisites:
- The NFS share that you will be using as a back end should already be properly configured.
- The node hosting the OpenStack volume service should have read/write access to the NFS share.
- You have
rootaccess to the node hosting the OpenStack volume service.
Assumptions:
- Your OpenStack deployment was not provisioned through the Red Hat Enterprise Linux OpenStack Platform Installer.
- Your OpenStack Block Storage service uses the default back end (which uses the back end name
lvm, as deployed by Packstack).
6.1.Configure SELinux
If a client has SELinux enabled, you should also enable the virt_use_nfs Boolean if the client requires access to NFS volumes on an instance. To enable this Boolean (and make it persistent through reboots), run the following command as root:
# setsebool -P virt_use_nfs on
Run this command on all client hosts that require access to NFS volumes on an instance. This includes all Compute nodes.
6.3.Create a new back end definition
By default, Packstack creates a back end definition for LVM in /etc/cinder/cinder.conf:
[lvm]iscsi_helper=lioadmvolume_group=cinder-volumesiscsi_ip_address=volume_driver=cinder.volume.drivers.lvm.LVMISCSIDrivervolume_backend_name=lvm
After defining the NFS share in /etc/cinder/cinder.conf, you can now configure an additional back end definition for it. To do so:
- Log in as
rootto the node hosting the OpenStack volume service. Create a new definition for the NFS back end and set the volume service to use the file defining the NFS share (namely,
/etc/cinder/nfs_share):# openstack-config --set /etc/cinder/cinder.conf nfs nfs_shares_config /etc/cinder/nfs_shares
Here, we use the name
nfsbackendas a definition name.Configure the volume service to use the NFS volume driver, namely
cinder.volume.drivers.nfs.NfsDriver:# openstack-config --set /etc/cinder/cinder.conf nfs volume_driver cinder.volume.drivers.nfs.NfsDriver
Define a volume back end name for the NFS back end (the following command uses the name
nfs):# openstack-config --set /etc/cinder/cinder.conf nfs volume_backend_name nfsbackend
Add any mount options (
MOUNTOPTIONS) you need to the nfs_mount_options configuration key:# openstack-config --set /etc/cinder/cinder.conf nfs nfs_mount_options _MOUNTOPTIONS_
At this point, the following section should now appear in /etc/cinder/cinder.conf:
[nfs]nfs_shares_config = /etc/cinder/nfs_sharesvolume_driver = cinder.volume.drivers.nfs.NfsDrivervolume_backend_name = nfsbackendnfs_mount_options =
You can now enable the NFS back end. Back ends are enabled through the enabled_backends configuration key of /etc/cinder/cinder.conf. The default back end created by Packstack should already be listed there:
enabled_backends=lvm
Add the new NFS back end definition to this list, as in:
enabled_backends=lvm,nfs
Once the NFS back end is enabled, restart the OpenStack volume service:
# openstack-service restart cinder-volume
6.4.Create a volume type for the NFS back end
The new NFS back end is now available, but cannot be used yet when creating new volumes. To configure new volumes to use this NFS back end, you need to first create a volume type for it.
View the existing volume types. By default, a volume type should already exist for the lvm back end (namely, iscsi):
+--------------------------------------+-------+ | ID | Name | +--------------------------------------+-------+ | f8d31dc8-a20e-410c-81bf-6b0a971c61a0 | iscsi | +--------------------------------------+-------+
Create a new volume type named
nfstypefor the NFS back end:# cinder type-create nfstype
Configure the
nfstypevolume type to use the NFS back end through the back end’s name (namely,nfsbackend):# cinder type-key nfstype set volume_backend_name=nfsbackend
Verify that the new type was created and configured correctly:
+--------------------------------------+---------+| ID | Name |+--------------------------------------+---------+| bbff44b5-52b1-43d6-beb4-83aa2d20bc59 | nfstype || f8d31dc8-a20e-410c-81bf-6b0a971c61a0 | iscsi |+--------------------------------------+---------++-----------------------+-------+---------------------------------------+| ID | Name | extra_specs |+-----------------------+-------+---------------------------------------+|bbff44b5-~-83aa2d20bc59|nfstype|{u'volume_backend_name': u'nfsbackend'}||f8d31dc8-~-6b0a971c61a0| iscsi | {u'volume_backend_name': u'lvm'} |+-----------------------+-------+---------------------------------------+
Note
You can also create and configure volume types through the dashboard. For more information, see Section4.2.3, “Group Volume Settings with Volume Types”.
6.5.Test the new NFS back end
To test the new NFS back end, create a new volume named nfsvolume while invoking the volume type nfstype:
+---------------------+--------------------------------------+| Property | Value |+---------------------+--------------------------------------+| attachments | [] || availability_zone | nova || bootable | false || created_at | 2015-01-06T05:14:09.271114 || display_description | None || display_name | nfsvolume || encrypted | False || id | 0cd7ac45-622a-47b0-9503-7025bbedc8ed || metadata | {} || size | 1 || snapshot_id | None || source_volid | None || status | creating || volume_type | nfstype |+---------------------+--------------------------------------+Once the volume is successfully created, check the NFS share (on the NFS server). A corresponding volume (whose name contains the ID of the newly-created volume) should appear there:
drwxrwxrwx. 2 root root 4.0K Jan 6 15:14 .drwxr-xr-x. 18 root root 4.0K Jan 5 04:03 ..-rw-rw-rw-. 1 nfsnobody nfsnobody 1.0G Jan 6 15:14+ +volume-0cd7ac45-622a-47b0-9503-7025bbedc8ed
