NexentaVolumeDriver - Revision history

Fifieldt at 18:03, 15 May 2014

2014-05-15T18:03:54Z

Ryan Lane: Text replace - "NOTOC" to ""

2013-02-17T23:31:18Z

Text replace - "__NOTOC__" to ""

Oleg at 18:52, 21 November 2011

2011-11-21T18:52:45Z

Yorik at 07:07, 21 November 2011

2011-11-21T07:07:03Z

Yorik at 07:00, 21 November 2011

2011-11-21T07:00:28Z

Yorik at 06:50, 21 November 2011

2011-11-21T06:50:15Z

Yorik at 15:52, 11 November 2011

2011-11-11T15:52:47Z

New page

__NOTOC__
* '''Launchpad Entry''': [https://blueprints.launchpad.net/nova/+spec/nexenta-volume-driver nexenta-volume-driver]
* '''Created''': 11 Nov 2011
* '''Contributors''': Yuriy Taraday

== Summary ==

We would like to introduce the [[NexentaStor]] support for the nova-volume service. This blueprint proposes the driver based on the iSCSI driver already integrated into the [[OpenStack]] nova-volume service, with the basic capabilities to create, export and delete volumes and snapshots.

The driver can interact with the [[NexentaStor]] Appliance using its REST API, or using DBus API. The default API is REST, and the DBus requires patched libdbus to function properly.

The proposal is to add [[NexentaStor]] driver to the nova-volume service.

== Release Note ==

[[NexentaStor]] Appliance is NAS/SAN software platform designed for building reliable and fast network storage arrays. The [[NexentaStor]] is based on the [[OpenSolaris]] and uses ZFS as a disk management system. [[NexentaStor]] can serve as a storage node for the [[OpenStack]] and provide block-level volumes for the virtual servers via iSCSI protocol.

=== Requirements ===

* Openstack nova-volume service installed
* [[NexentaStor]] Appliance installed and configured
* Dedicated ‘volume’ object created on appliance

== Rationale ==

[[NexentaStor]] Appliance provides reliable block-level volumes which are easy to manage via simple REST interface. It automates many common storage administration tasks. It is intended to be used with commodity hardware and basically is vendor-independent. This makes [[NexentaStor]] Appliance software useful as a base for storage nodes in IaaS clouds.

== User stories ==

User installs nova-volume service on the Openstack node and configures volume_driver, specifies communication transport and IP address of the [[NexentaStor]] appliance. Additional parameters for volumes can be specified in the flag file, i.e. block size. User can then create volumes with standard Nova API calls.

=== Nexenta Appliance Configuration ===

To get the volumes stored to the Nexenta appliance, it has to be configured appropriately. Configuration of appliance includes the following steps:
* install and configure [[NexentaStor]] software via management console and web interface using initial configuration wizard;
* use management console or web interface to create ZFS volume, for example, ‘nova’;
* specify base volume name in the nova.conf on the Openstack node that runs nova-volume.

=== User Experience ===

The [[NexentaStor]] appliance using SAS disk drives and connected to the Compute node by 1Gbps Ethernet provides following input and output rates:
* up to 60 Mbytes per second on sequential writes
* up to 132 Mbytes per second on random reads
* up to 1000 volumes per appliance tested

== Assumptions ==

This driver assumes user has installed [[NexentaStor]] software on at least one appliance and configured it to have a logical volume dedicated to Openstack volumes.

== Design ==

Driver extends iSCSI driver in the same way as all SAN drivers. All operations are performed using one of two transport modules: either D-Bus or JSON RPC transport supported.

=== Volumes Back-End ===

ZFS zvols are used as base for exported volumes. Zvol is a ZFS entity that essentialy is virtual block device. Its flexible configuration allows block sizes from 512 bytes to 128 Kbytes, and use of advanced ZFS specific features like built-in integrity control, deduplication and caching. Zvols can be sparse and consume only so much disk space as the size of actually written data.

The driver supports the following features of underlying ZFS zvols:
* block size can be specified in bytes or Kbytes with --nexenta_blocksize flag;
* use of sparse volumes can be configured with --nexenta_sparse flag;

=== Volumes Export ===

Common iSCSI initiator-target scheme is used for export. Each volume is exported through dedicated target which is placed in separate target group to ensure correct iSCSI LUN numbering.

== Implementation ==

Driver functionality is separated into three modules. Two modules implement transports: nexenta.jsonrpc for JSON RPC and nexenta.NZA for D-Bus. Latter requires patched libdbus installed in the system. The nexenta.volume module contains the driver code.

Minor exception handling issue was fixed in the main nova code to enhance the behavior of the driver.

=== Code Changes ===

Nexenta driver code should be included as package under nova.volume package.

== Test/Demo Plan ==

This need not be added or completed until the specification is nearing beta.

== Unresolved issues ==

* Currently one cannot delete a snapshot if there is a volume created from it due to Nexenta limitations.

== External links ==

* http://www.nexenta.com/ -- official Nexenta Systems Inc. website. Documentation and downloads for [[NexentaStor]] software.
* http://www.nexentastor.org/ -- [[NexentaStor]] Community website. Open source projects, discussion boards and community downloads.
* [http://www.nexentastor.org/projects/osvd/files]] -- driver's download page, you can find [[http://www.nexentastor.org/attachments/download/213/openstack-nexenta-driver.tar.bz2 driver itself] and [http://www.nexentastor.org/attachments/download/212/nexenta_dbus.diff.bz2 patch for libdbus] here.

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[[Category:Spec]]

@@ Line 46: / Line 46: @@
 * nexenta_user - name of user at Nexenta appliance with REST API access (e.g. admin);
 * nexenta_password - password for that user.
 === User Experience ===

@@ Line 1: / Line 1: @@
+{{OldDesignPage}}
 * '''Launchpad Entry''': [https://blueprints.launchpad.net/nova/+spec/nexenta-volume-driver nexenta-volume-driver]
 * '''Created''': 11 Nov 2011

@@ Line 34: / Line 34: @@
 To get the volumes stored to the Nexenta appliance, it has to be configured appropriately. Configuration of appliance includes the following steps:
 * install and configure [[NexentaStor]] software via management console and web interface using initial configuration wizard;
-* use management console or web interface to create ZFS volume, for example, ‘nova’;
+* use management console or web interface to create ZFS volume, for example, ‘nova-volumes’;
 * specify base volume name in the nova.conf on the Openstack node that runs nova-volume.
 === [[OpenStack]] Nova configuration ===
@@ Line 98: / Line 146: @@
 == Test/Demo Plan ==
-This need not be added or completed until the specification is nearing beta.
+You can see the demonstration of the function of this driver in this video:
 == Unresolved issues ==

@@ Line 87: / Line 87: @@
 * http://www.nexentastor.org/ -- [[NexentaStor]] Community website. Open source projects, discussion boards and community downloads.
 * [http://www.nexentastor.org/projects/osvd/files]] -- driver's download page, you can find [[http://www.nexentastor.org/attachments/download/213/openstack-nexenta-driver.tar.bz2 driver itself] and [http://www.nexentastor.org/attachments/download/212/nexenta_dbus.diff.bz2 patch for libdbus] here.
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 [[Category:Spec]]