Libvirt external snapshot with GlusterFS - Revision history

Pat: /* Command overview */

2014-05-14T15:07:56Z

Command overview

← Older revision		Revision as of 17:07, 14 May 2014
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	# when finished, have Qemu finish it (TODO: check whether we would have to install a dirty block tracer at some point):		# when finished, have Qemu finish it (TODO: check whether we would have to install a dirty block tracer at some point):
	# EDIT PKL: No we don't need to trace the dirty blocks as qemu already does something similar. After the block commit, both disks are in a way synchronized. I.e. if a write operation is performed, it is written to the snapshot image as well as to base image. After the block-job-complete command the write operations are written to the base image only		# EDIT PKL: No we don't need to trace the dirty blocks as qemu already does something similar. After the block commit,
			# both disks are in a way synchronized. I.e. if a write operation is performed, it is written to the snapshot image as
			# well as to base image. After the block-job-complete command the write operations are written to the base image only
	virsh qemu-monitor-command 8196bb77-7478-4bfb-a6ea-52b3a2c65eba --pretty '{"execute": "block-job-complete", "arguments": { "device": "drive-virtio-disk0"} }'		virsh qemu-monitor-command 8196bb77-7478-4bfb-a6ea-52b3a2c65eba --pretty '{"execute": "block-job-complete", "arguments": { "device": "drive-virtio-disk0"} }'

2014-05-14T15:07:39Z

Command overview

← Older revision		Revision as of 17:07, 14 May 2014
Line 219:		Line 219:

	# when finished, have Qemu finish it (TODO: check whether we would have to install a dirty block tracer at some point):		# when finished, have Qemu finish it (TODO: check whether we would have to install a dirty block tracer at some point):
			# EDIT PKL: No we don't need to trace the dirty blocks as qemu already does something similar. After the block commit, both disks are in a way synchronized. I.e. if a write operation is performed, it is written to the snapshot image as well as to base image. After the block-job-complete command the write operations are written to the base image only
	virsh qemu-monitor-command 8196bb77-7478-4bfb-a6ea-52b3a2c65eba --pretty '{"execute": "block-job-complete", "arguments": { "device": "drive-virtio-disk0"} }'		virsh qemu-monitor-command 8196bb77-7478-4bfb-a6ea-52b3a2c65eba --pretty '{"execute": "block-job-complete", "arguments": { "device": "drive-virtio-disk0"} }'

2014-05-14T13:06:10Z

VSS & Qemu-GA

@@ Line 237: / Line 237: @@
 Volume Shadow Copy Service error: Unexpected error querying for the iVssWriterCallback interface, hr = 0x8007005, Access is denied.
 </pre>
 [[Category:Snippets]]

2014-05-09T15:32:17Z

Command overview

← Older revision		Revision as of 17:32, 9 May 2014
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	virsh edit 8196bb77-7478-4bfb-a6ea-52b3a2c65eba		virsh edit 8196bb77-7478-4bfb-a6ea-52b3a2c65eba
	</source>		</source>

			== VSS & Qemu-GA ==

			'''TODO''': at the moment, the following error appears in the Windows Application Log:
			<pre>
			Volume Shadow Copy Service error: Unexpected error querying for the iVssWriterCallback interface, hr = 0x8007005, Access is denied.
			</pre>

	[[Category:Snippets]]		[[Category:Snippets]]

2014-05-09T15:30:55Z

Cleanup/Commit (Online)

@@ Line 200: / Line 200: @@
 # remove the snapshot file:
 rm /var/virtualization/vm-templates/5b77d2f6-061f-410c-8ee7-9e61da6f1927/bbf7796f-90bf-45ab-8645-2894f5dae727.snap01.qcow2
 </source>
 [[Category:Snippets]]

2014-05-09T14:56:15Z

Part 2: Create the snapshot using virsh

← Older revision		Revision as of 16:56, 9 May 2014
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	</source>		</source>

	~~Ex.~~		Examples:
	<pre>		<pre>
	~~vm-test-02~~ ~ # virsh snapshot-create d4572522-eae4-4e3e-ab36-618ae4a91fb4 snap.xml --disk-only --atomic		~ # virsh snapshot-create d4572522-eae4-4e3e-ab36-618ae4a91fb4 snap.xml --disk-only --atomic
	Domain snapshot snap created from 'snap.xml'		Domain snapshot snap created from 'snap.xml'
			</pre>

			<pre>
			~ # virsh snapshot-create 8196bb77-7478-4bfb-a6ea-52b3a2c65eba kvm-0022-snapshot-01.xml --disk-only --atomic --quiesce
	</pre>		</pre>

2014-05-09T08:48:50Z

Cleanup/Commit (Online)

@@ Line 136: / Line 136: @@
      },
      "id": "libvirt-28"
+}
 ~ #
 </pre>
-The block job is running on 100% for a long time until finished.
+Now check the images again:
 <pre>
 ~ # virsh qemu-monitor-command --hmp e43a2954-3914-465f-9391-9e63b52ec2f5 "info block"

2014-05-09T08:29:04Z

Cleanup/Commit (Online)

← Older revision		Revision as of 10:29, 9 May 2014
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	# update the XML to have it point to the original file again		# update the XML to have it point to the original file again
	virsh edit e43a2954-3914-465f-9391-9e63b52ec2f5		virsh edit e43a2954-3914-465f-9391-9e63b52ec2f5

			# remove the snapshot file:
			rm /var/virtualization/vm-templates/5b77d2f6-061f-410c-8ee7-9e61da6f1927/bbf7796f-90bf-45ab-8645-2894f5dae727.snap01.qcow2
	</source>		</source>

	[[Category:Snippets]]		[[Category:Snippets]]

2014-05-09T08:27:31Z

Cleanup/Commit (Online)

← Older revision		Revision as of 10:27, 9 May 2014
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	<source lang='bash'>		<source lang='bash'>
	virsh snapshot-delete e43a2954-3914-465f-9391-9e63b52ec2f5 --current --metadata		virsh snapshot-delete e43a2954-3914-465f-9391-9e63b52ec2f5 --current --metadata

			# update the XML to have it point to the original file again
			virsh edit e43a2954-3914-465f-9391-9e63b52ec2f5
	</source>		</source>

	~~'''TODO''': update the XML~~
	[[Category:Snippets]]		[[Category:Snippets]]

2014-05-08T16:12:46Z

Cleanup

@@ Line 89: / Line 89: @@
 </pre>
-=== Cleanup ===
+=== Cleanup/Commit (Offline) ===
 Unfortunately libvirt does not know how to remove an external snapshot and still has some issues when trying to <code>blockcommit</code> on a file with native-gluster backing file:
@@ Line 120: / Line 120: @@
 rm /var/virtualization/vm-templates/5b77d2f6-061f-410c-8ee7-9e61da6f1927/de7c7c4e-8664-4ac7-b559-53fd52ec461c.snap01.qcow2
-# TODO: unregister the snapshot in libvirt
+# unregister the snapshot in libvirt
 </source>
 [[Category:Snippets]]