openstack-manuals/doc/install-guide-debconf/source/cinder-storage-install.rst

Install and configure a storage node

This section describes how to install and configure storage nodes for the Block Storage service. For simplicity, this configuration references one storage node with an empty local block storage device. The instructions use /dev/sdb, but you can substitute a different value for your particular node.

The service provisions logical volumes on this device using the LVM <Logical Volume Manager (LVM)> driver and provides them to instances via iSCSI <iSCSI Qualified Name (IQN)> transport. You can follow these instructions with minor modifications to horizontally scale your environment with additional storage nodes.

Prerequisites

Before you install and configure the Block Storage service on the storage node, you must prepare the storage device.

Note

Perform these steps on the storage node.

1. Create the LVM physical volume /dev/sdb:

   # pvcreate /dev/sdb
   
   Physical volume "/dev/sdb" successfully created

2. Create the LVM volume group cinder-volumes:

   # vgcreate cinder-volumes /dev/sdb
   
   Volume group "cinder-volumes" successfully created

   The Block Storage service creates logical volumes in this volume group.

3. Only instances can access Block Storage volumes. However, the underlying operating system manages the devices associated with the volumes. By default, the LVM volume scanning tool scans the /dev directory for block storage devices that contain volumes. If projects use LVM on their volumes, the scanning tool detects these volumes and attempts to cache them which can cause a variety of problems with both the underlying operating system and project volumes. You must reconfigure LVM to scan only the devices that contain the cinder-volume volume group. Edit the /etc/lvm/lvm.conf file and complete the following actions:

   • In the devices section, add a filter that accepts the /dev/sdb device and rejects all other devices:

     devices {
     ...
     filter = [ "a/sdb/", "r/.*/"]

     Each item in the filter array begins with a for accept or r for reject and includes a regular expression for the device name. The array must end with r/.*/ to reject any remaining devices. You can use the vgs -vvvv command to test filters.

     Warning

     If your storage nodes use LVM on the operating system disk, you must also add the associated device to the filter. For example, if the /dev/sda device contains the operating system:

     filter = [ "a/sda/", "a/sdb/", "r/.*/"]

     Similarly, if your compute nodes use LVM on the operating system disk, you must also modify the filter in the /etc/lvm/lvm.conf file on those nodes to include only the operating system disk. For example, if the /dev/sda device contains the operating system:

     filter = [ "a/sda/", "r/.*/"]

Install and configure components

1. Install the packages:

   # apt-get install cinder-volume

   Respond to prompts for database management <debconf/debconf-dbconfig-common>, Identity service credentials <debconf/debconf-keystone-authtoken>, service endpoint registration <debconf/debconf-api-endpoints>, and message broker credentials <debconf/debconf-rabbitmq>.

2. Edit the /etc/cinder/cinder.conf file and complete the following actions:

   • In the [DEFAULT] section, configure the my_ip option:

     [DEFAULT]
     ...
     my_ip = MANAGEMENT_INTERFACE_IP_ADDRESS

     Replace MANAGEMENT_INTERFACE_IP_ADDRESS with the IP address of the management network interface on your storage node, typically 10.0.0.41 for the first node in the example architecture <overview-example-architectures>.

   • In the [DEFAULT] section, configure the location of the Image service API:

     [DEFAULT]
     ...
     glance_api_servers = http://controller:9292

Finalize installation

1. Restart the Block Storage volume service including its dependencies:

   # service tgt restart
   # service cinder-volume restart