madorn/gist:9793286

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    Havana: Cinder NFS Backend

Intro

Cinder maintains an iSCSI connection between the cinder-volume and compute node when utilizing the LVM driver (cinder.volume.drivers.lvm.LVMISCSIDriver).
If one uses the NFS driver for a backend (cinder.volume.drivers.nfs.NfsDriver), the volume is served to the compute node via NFS share.
Scenario


Controller (192.168.2.1)

apt-get install cinder-api

apt-get install cinder-scheduler

cat /etc/cinder/cinder.conf
[DEFAULT]
rootwrap_config = /etc/cinder/rootwrap.conf
api_paste_confg = /etc/cinder/api-paste.ini
iscsi_helper = tgtadm
volume_name_template = volume-%s
verbose = True
auth_strategy = keystone
state_path = /var/lib/cinder
lock_path = /var/lock/cinder
volumes_dir = /var/lib/cinder/volumes
sql_connection = mysql://cinder:notcinder@192.168.2.1/cinder
my_ip= 192.168.2.1
enabled_backends=cinder-volumes-1-driver

Compute (192.168.2.2)

apt-get install nova-compute

apt-get install nfs-common

Cinder-Volume (192.168.2.3)

apt-get install cinder-volume

apt-get install nfs-common

cat /etc/cinder/cinder.conf
[DEFAULT]
rootwrap_config = /etc/cinder/rootwrap.conf
api_paste_confg = /etc/cinder/api-paste.ini
iscsi_helper = tgtadm
volume_name_template = volume-%s
verbose = True
auth_strategy = keystone
state_path = /var/lib/cinder
lock_path = /var/lock/cinder
volumes_dir = /var/lib/cinder/volumes
sql_connection = mysql://cinder:notcinder@192.168.2.1/cinder
my_ip= 192.168.2.3
rabbit_host = 192.168.2.1
enabled_backends=cinder-volumes-1-driver
[cinder-volumes-1-driver]
nfs_shares_config=/etc/cinder/shares.txt
volume_driver=cinder.volume.drivers.nfs.NfsDriver
volume_backend_name=NFS

NFS-Server 1 (192.168.2.50)

apt-get install nfs-kernel-server

cat /etc/exports
/share1   192.168.2.0/24(rw,fsid=0,insecure,no_subtree_check,async)

NFS-Server 2 (192.168.2.60)

apt-get install nfs-kernel-server

cat /etc/exports
/share2   192.168.2.0/24(rw,fsid=0,insecure,no_subtree_check,async)
Volume Creation

When one creates a cinder volume utilizing a NFS backend, a loop device is created in one of the specified NFS shares (/etc/cinder/shares.txt).
The driver determines which share the loop device should be created on based off available capacity for volume size specifed.
Volume Attach

When one attaches a volume to an instance, the compute node mounts the nfs server share. The volume (loopback device) that resides in the share is served to the instance via libvirt.
Notes


Attaching one volume to multiple vm's is prohibited.
Snapshots are prohibited.