Bug 1431635

Summary:	Missing important preparation steps for planned HE-to-HE migration
Product:	Red Hat Enterprise Virtualization Manager	Reporter:	Denis Chaplygin <dchaplyg>
Component:	Documentation	Assignee:	rhev-docs <rhev-docs>
Status:	CLOSED DUPLICATE	QA Contact:	rhev-docs <rhev-docs>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	unspecified	CC:	dchaplyg, gklein, gveitmic, lbopf, lsurette, rbalakri, srevivo, thildred, ykaul, ylavi
Target Milestone:	---
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Hardware:	Unspecified
OS:	Unspecified
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Fixed In Version:		Doc Type:	If docs needed, set a value
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Last Closed:	2017-03-29 12:55:54 UTC	Type:	Bug
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oVirt Team:	Docs	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1417518, 1422486
Bug Blocks:

Description Denis Chaplygin 2017-03-13 13:45:02 UTC

Description of problem:

HE-to-HE migration could lead to stale SPM or duplicating SPM_IDs. To prevent that, two steps should be done:

* Before migration manually set SPM host to any of non-HE hosts.
* After migration old HE hosts should be redeployed as soon as possible.

Those steps above should be documented.

Comment 1 Yaniv Lavi 2017-03-14 12:46:49 UTC

We don't have a guide for HE-to-HE today?
Can you provide the info on the flow for this process? What is the use case?

Comment 2 Denis Chaplygin 2017-03-14 12:55:32 UTC

I'm not sure if we have a HE-to-HE guide today.

Possible use cases are listed my Simone in BZ1417518. Let me copy them here:

Migrating from an NFS based hosted-engine deployed to an iSCSI one or from an iSCSI LUN to one on different target and so on (just because you have to decommission the storage you are using for hosted-engine) without the need to power-down the whole datacenter. We already have different users asking for this; customers are also asking to backport to 4.0.

Comment 3 Lucy Bopf 2017-03-29 12:55:54 UTC

We will use bug 1420604 to track items related to SHE backup and restore (and migration), and use the information in this bug's description to ensure that migration prerequisites are covered.

Closing as duplicate.

*** This bug has been marked as a duplicate of bug 1420604 ***

Comment 4 Germano Veit Michel 2017-04-11 06:10:39 UTC

(In reply to Denis Chaplygin from comment #0)
> * After migration old HE hosts should be redeployed as soon as possible.

If we recommend to switch the old HE hosts to maintenance mode before starting the procedure it would be safer, wouldn't it? It would release their locks, right?

Comment 5 Denis Chaplygin 2017-04-11 07:15:50 UTC

Yes. Putting them to the maintenance mode in prior is the best way to do migration.