kolla-ansible/doc/source/reference/storage/cinder-guide.rst
chenxing b7ca065edf Remove `hnas_iscsi` from the supported storage backends list of Cinder
The Hitachi NAS Platform iSCSI driver was marked as not supported by
Cinder in the Ocata realease[1].

[1] https://review.opendev.org/#/c/444287/

Change-Id: I1a25789374fddaefc57bc59badec06f91ee6a52a
Closes-Bug: #1832821
2019-06-24 09:04:14 +00:00

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5.9 KiB
ReStructuredText

.. _cinder-guide:
======================
Cinder - Block storage
======================
Overview
~~~~~~~~
Cinder can be deployed using Kolla and supports the following storage
backends:
* ceph
* hnas_nfs
* iscsi
* lvm
* nfs
LVM
~~~
When using the ``lvm`` backend, a volume group should be created on each
storage node. This can either be a real physical volume or a loopback mounted
file for development. Use ``pvcreate`` and ``vgcreate`` to create the volume
group. For example with the devices ``/dev/sdb`` and ``/dev/sdc``:
.. code-block:: console
<WARNING ALL DATA ON /dev/sdb and /dev/sdc will be LOST!>
pvcreate /dev/sdb /dev/sdc
vgcreate cinder-volumes /dev/sdb /dev/sdc
During development, it may be desirable to use file backed block storage. It
is possible to use a file and mount it as a block device via the loopback
system.
.. code-block:: console
free_device=$(losetup -f)
fallocate -l 20G /var/lib/cinder_data.img
losetup $free_device /var/lib/cinder_data.img
pvcreate $free_device
vgcreate cinder-volumes $free_device
Enable the ``lvm`` backend in ``/etc/kolla/globals.yml``:
.. code-block:: yaml
enable_cinder_backend_lvm: "yes"
.. note::
There are currently issues using the LVM backend in a multi-controller setup,
see `_bug 1571211 <https://launchpad.net/bugs/1571211>`__ for more info.
NFS
~~~
To use the ``nfs`` backend, configure ``/etc/exports`` to contain the mount
where the volumes are to be stored:
.. code-block:: console
/kolla_nfs 192.168.5.0/24(rw,sync,no_root_squash)
In this example, ``/kolla_nfs`` is the directory on the storage node which will
be ``nfs`` mounted, ``192.168.5.0/24`` is the storage network, and
``rw,sync,no_root_squash`` means make the share read-write, synchronous, and
prevent remote root users from having access to all files.
Then start ``nfsd``:
.. code-block:: console
systemctl start nfs
On the deploy node, create ``/etc/kolla/config/nfs_shares`` with an entry for
each storage node:
.. code-block:: console
storage01:/kolla_nfs
storage02:/kolla_nfs
Finally, enable the ``nfs`` backend in ``/etc/kolla/globals.yml``:
.. code-block:: yaml
enable_cinder_backend_nfs: "yes"
Validation
~~~~~~~~~~
Create a volume as follows:
.. code-block:: console
openstack volume create --size 1 steak_volume
<bunch of stuff printed>
Verify it is available. If it says "error", then something went wrong during
LVM creation of the volume.
.. code-block:: console
openstack volume list
+--------------------------------------+--------------+-----------+------+-------------+
| ID | Display Name | Status | Size | Attached to |
+--------------------------------------+--------------+-----------+------+-------------+
| 0069c17e-8a60-445a-b7f0-383a8b89f87e | steak_volume | available | 1 | |
+--------------------------------------+--------------+-----------+------+-------------+
Attach the volume to a server using:
.. code-block:: console
openstack server add volume steak_server 0069c17e-8a60-445a-b7f0-383a8b89f87e
Check the console log to verify the disk addition:
.. code-block:: console
openstack console log show steak_server
A ``/dev/vdb`` should appear in the console log, at least when booting cirros.
If the disk stays in the available state, something went wrong during the
iSCSI mounting of the volume to the guest VM.
Cinder LVM2 backend with iSCSI
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
As of Newton-1 milestone, Kolla supports LVM2 as cinder backend. It is
accomplished by introducing two new containers ``tgtd`` and ``iscsid``.
``tgtd`` container serves as a bridge between cinder-volume process and a
server hosting Logical Volume Groups (LVG). ``iscsid`` container serves as
a bridge between nova-compute process and the server hosting LVG.
In order to use Cinder's LVM backend, a LVG named ``cinder-volumes`` should
exist on the server and following parameter must be specified in
``globals.yml``:
.. code-block:: yaml
enable_cinder_backend_lvm: "yes"
For Ubuntu and LVM2/iSCSI
-------------------------
``iscsd`` process uses configfs which is normally mounted at
``/sys/kernel/config`` to store discovered targets information, on centos/rhel
type of systems this special file system gets mounted automatically, which is
not the case on debian/ubuntu. Since ``iscsid`` container runs on every nova
compute node, the following steps must be completed on every Ubuntu server
targeted for nova compute role.
- Add configfs module to ``/etc/modules``
- Rebuild initramfs using: ``update-initramfs -u`` command
- Stop ``open-iscsi`` system service due to its conflicts
with iscsid container.
Ubuntu 16.04 (systemd):
``systemctl stop open-iscsi; systemctl stop iscsid``
- Make sure configfs gets mounted during a server boot up process. There are
multiple ways to accomplish it, one example:
.. code-block:: console
mount -t configfs /etc/rc.local /sys/kernel/config
.. note::
There is currently an issue with the folder /sys/kernel/config as it is
either empty or does not exist in several operating systems,
see `_bug 1631072 <https://bugs.launchpad.net/kolla/+bug/1631072>`__ for more info
Cinder backend with external iSCSI storage
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In order to use external storage system (like the ones from EMC or NetApp)
the following parameter must be specified in ``globals.yml``:
.. code-block:: yaml
enable_cinder_backend_iscsi: "yes"
Also ``enable_cinder_backend_lvm`` should be set to ``no`` in this case.
Skip Cinder prechecks for Custom backends
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In order to use custom storage backends which currently not yet implemented
in Kolla, the following parameter must be specified in ``globals.yml``:
.. code-block:: yaml
skip_cinder_backend_check: True
All configuration for custom NFS backend should be performed
via ``cinder.conf`` in config overrides directory.