Attach a Cloud Block Storage volume to an OnMetal server
Last updated on: 2019-12-20
Authored by: Catherine Richardson
Your OnMetal server can connect to a Cloud Block Storage volume.
Connecting an OnMetal server to a Cloud Block Storage volume is useful if you need more than 32 GB of storage but do not have a requirement for the fast I/O normally provided by an OnMetal server. Using an OnMetal server with Cloud Block Storage is particularly useful for OnMetal Compute and Memory v1 flavors.
Attach a volume
To use the CLI in your terminal window, use the following procedure to attach a volume to your OnMetal server. (For information about installing the nova client, see Installing python-novaclient on Linux and Mac OS.) The procedure assumes that the server instance and volume already exist.
-
Set up the instance and the volume with their IDs as environment variables so that they are in the environment for use by subsequently executed commands.
$ export INSTANCE=62f3ac8d-13f1-49a4-90ed-ab3c62eb302e $ export VOLUME=3e7af99d-655f-4af1-93bb-9160ee505d9f -
Attach the instance. You can ignore the return value.
$ nova volume-attach $INSTANCE $VOLUME +----------+--------------------------------------+ | device | /dev/sdb | | id | 3e7af99d-655f-4af1-93bb-9160ee505d9f | | serverId | 62f3ac8d-13f1-49a4-90ed-ab3c62eb302e | | volumeId | 3e7af99d-655f-4af1-93bb-9160ee505d9f | +----------+--------------------------------------+ -
Get the volume metadata from the instance. Each attached volume has a metadata key. These keys are named volumes_$VOLUME and are a JSON string.
$ nova show $INSTANCE +--------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Property | Value | +--------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | OS-DCF:diskConfig | MANUAL | | OS-EXT-STS:power_state | 1 | | OS-EXT-STS:task_state | - | | OS-EXT-STS:vm_state | active | | RAX-PUBLIC-IP-ZONE-ID:publicIPZoneId | 24e57d104262c2c4d0c7f1738a440384d3727ca9d93809f84ef54cad | | accessIPv4 | 50.57.63.76 | | accessIPv6 | | | config_drive | True | | created | 2015-07-17T00:18:03Z | | flavor | OnMetal IO v1 (onmetal-io1) | | hostId | 3cff0ecc09185d0bc7454019c7caee299c1a584a6a686910b1c77586 | | id | 62f3ac8d-13f1-49a4-90ed-ab3c62eb302e | | image | OnMetal - Ubuntu 14.04 LTS (Trusty Tahr) (c199db85-c6f9-4284-b9ec-16327ee2fc84) | | key_name | jim | | metadata | {"volumes_3e7af99d-655f-4af1-93bb-9160ee505d9f": "{\"target_iqn\": \"iqn.2010-11.com.rackspace:3e7af99d-655f-4af1-93bb-9160ee505d9f\", \"target_portal\": \"10.190.254.69:3260\", \"initiator_name\": \"iqn.2008-10.org.openstack:9f956df7-3412-48e1-ac8b-017e2d643cf9\"}"} | | name | jim-test-io3 | | private network | 10.184.255.220 | | progress | 100 | | public network | 50.57.63.76 | | status | ACTIVE | | tenant_id | 5956439 | | updated | 2015-07-17T00:22:58Z | | user_id | 18c93a9ae8d9446b80543fdd799638ef | +--------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ -
Go into the instance to complete the setup.
$ export IP=50.57.63.76 $ ssh root@$IP -
From inside the instance, perform all instructions as root.
-
Set some variables from the metadata.
$ export TARGET_IQN=iqn.2010-11.com.rackspace:3e7af99d-655f-4af1-93bb-9160ee505d9f $ export TARGET_PORTAL=10.190.254.69:3260 $ export INITIATOR_NAME=iqn.2008-10.org.openstack:9f956df7-3412-48e1-ac8b-017e2d643cf9 -
Ensure that the iSCSI tooling is installed.
For the Ubuntu operating system and Debian:
$ apt-get update $ apt-get install open-iscsiFor Fedora and Centos:
$ yum install iscsi-initiator-utils -
Discover what block devices exist, so that you can find your new one later. The output might vary depending on the server flavor.
$ lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 28.9G 0 disk sda1 8:1 0 28.8G 0 part / sda2 8:2 0 64M 0 part sdb 8:16 0 1.5T 0 disk sdc 8:32 0 1.5T 0 disk -
Set up the iSCSI client.
$ echo InitiatorName=$INITIATOR_NAME > /etc/iscsi/initiatorname.iscsi -
Attach the Cloud Block Storage volume.
$ iscsiadm -m discovery --type sendtargets --portal $TARGET_PORTAL 10.190.254.69:3260,1 iqn.2010-11.com.rackspace:3e7af99d-655f-4af1-93bb-9160ee505d9f 10.13.236.75:3260,1 iqn.2010-11.com.rackspace:3e7af99d-655f-4af1-93bb-9160ee505d9f $ iscsiadm -m node --targetname=$TARGET_IQN --portal $TARGET_PORTAL --login Logging in to [iface: default, target: iqn.2010-11.com.rackspace:3e7af99d-655f-4af1-93bb-9160ee505d9f, portal: 10.190.254.69,3260] (multiple) Login to [iface: default, target: iqn.2010-11.com.rackspace:3e7af99d-655f-4af1-93bb-9160ee505d9f, portal: 10.190.254.69,3260] successful. -
Find the block device that was just added. In this case, it is sdd.
$ lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 28.9G 0 disk sda1 8:1 0 28.8G 0 part / sda2 8:2 0 64M 0 part sdb 8:16 0 1.5T 0 disk sdc 8:32 0 1.5T 0 disk sdd 8:48 0 2G 0 disk
Now you can use the device, just like on other cloud servers. For more information, see Prepare your Cloud Block Storage volume.
Detach a volume
To use the CLI in your terminal window, use the following procedure to detach a volume from your OnMetal server.
-
From inside the instance, perform all commands as root.
-
Unmount file systems. (For instructions, see Detach and delete Cloud Block Storage volumes).
-
Disconnect the volume.
$ iscsiadm -m node --targetname=$TARGET_IQN --portal $TARGET_PORTAL --logout Logging out of session [sid: 1, target: iqn.2010-11.com.rackspace:3e7af99d-655f-4af1-93bb-9160ee505d9f, portal: 10.190.254.69,3260] Logout of [sid: 1, target: iqn.2010-11.com.rackspace:3e7af99d-655f-4af1-93bb-9160ee505d9f, portal: 10.190.254.69,3260] successful. -
From the local machine, detach the volume using nova. If you detach before disconnecting, the volume will remain in detaching status until the preceding command is run and the following command is run again.
$ nova volume-detach $INSTANCE $VOLUME
Note: When volumes are attached to an instance, you can not delete a volume from that instance. The instance will succeed if you detach the volume, than delete the volume again.
©2020 Rackspace US, Inc.
Except where otherwise noted, content on this site is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License
