SheepdogSupport - Revision history

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

2013-02-17T23:31:03Z

Text replace - "NovaSpec" to "NovaSpec"

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

2013-02-17T23:30:04Z

Text replace - "__NOTOC__" to ""

Kazutaka at 01:03, 17 November 2010

2010-11-17T01:03:45Z

Kazutaka at 11:04, 15 November 2010

2010-11-15T11:04:30Z

Kazutaka at 09:48, 15 November 2010

2010-11-15T09:48:49Z

New page

__NOTOC__
* '''Launchpad Entry''': [[NovaSpec]]:sheepdog-support
* '''Created''': 2010-11-15
* '''Contributors''': Kazutaka Morita, Tomonori Fujita

== Summary ==
Add Sheepdog support to Nova instances.

== Release Note ==
Sheepdog is a distributed block storage system for QEMU.
This proposes integrating Sheepdog into [[OpenStack]] and
providing highly available block volumes for VMs like Amazon EBS.
The details about Sheepdog are in http://www.osrg.net/sheepdog/.

== Rationale ==
Current implementation of volumes (iSCSI/AoE with LVM) is not fit for IaaS.
* the architecture is not scalable in capacity and performance
* LVM machine could become a SPOF
* If we take many LVM snapshots, the performance of volumes becomes terrible

== User stories ==

== Assumptions ==

== Design ==

== Implementation ==

create a new class '[[SheepdogDriver]]([[VolumeDriver]])' like the following:

<pre><nowiki>
class SheepdogDriver(VolumeDriver):
"""Executes commands relating to Sheepdog Volumes"""

def check_for_setup_error(self):
"""Returns an error if prerequisites aren't met"""
# TODO: check whether sheepdog is starting or not
pass

@defer.inlineCallbacks
def create_volume(self, volume):
"""Creates a sheepdog volume"""
yield self._try_execute("qemu-img create sheepdog:%s %s" %
(volume['name'], volume['size']))

@defer.inlineCallbacks
def delete_volume(self, volume):
"""Deletes a logical volume"""
yield self._try_execute("collie vdi delete %s" % volume['name'])

def ensure_export(self, context, volume):
"""Safely and synchronously recreates an export for a logical volume"""
# TODO: check whether volume['name'] exists
pass

@defer.inlineCallbacks
def create_export(self, context, volume):
"""Exports the volume"""
pass

@defer.inlineCallbacks
def remove_export(self, context, volume):
"""Removes an export for a logical volume"""
pass

@defer.inlineCallbacks
def discover_volume(self, volume):
"""Discover volume on a remote host"""
defer.returnValue("sheepdog:%s" % volume['name'])

@defer.inlineCallbacks
def undiscover_volume(self, volume):
"""Undiscover volume on a remote host"""
yield
</nowiki></pre>

----
[[Category:Spec]]

@@ Line 1: / Line 1: @@
-* '''Launchpad Entry''': [[NovaSpec]]:sheepdog-support
+* '''Launchpad Entry''': NovaSpec:sheepdog-support
 * '''Created''': 2010-11-15
 * '''Contributors''': Kazutaka Morita, Tomonori Fujita