Bug 1356198
| Summary: | [Docs] Must specify that changing cluster compat mode level (CL) to 3.6 requires VMs shut down first | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Virtualization Manager | Reporter: | Marina Kalinin <mkalinin> |
| Component: | Documentation | Assignee: | rhev-docs <rhev-docs> |
| Status: | CLOSED DUPLICATE | QA Contact: | rhev-docs <rhev-docs> |
| Severity: | urgent | Docs Contact: | |
| Priority: | urgent | ||
| Version: | 3.6.7 | CC: | dmoessne, gklein, lsurette, michal.skrivanek, mkalinin, rbalakri, sites-redhat, srevivo, ykaul, ylavi |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2016-07-19 11:28:12 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | Docs | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
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Description
Marina Kalinin
2016-07-13 16:14:14 UTC
As an admin I strongly disagree with the "solution" that all VMs be required to be shut down for a cluster upgrade. In many (most?) real-world clusters it is neither operationally nor politically feasible to shut down all VMs in the cluster at the same time! Further, it wouldn't work as a solution anyway; the HE VM _can't_ be shut down and have the cluster still be in a state where you could change the CV (outside of manually manipulating the DB directly). Please reconsider this! Thanks, Carl (In reply to Carl Thompson from comment #2) > As an admin I strongly disagree with the "solution" that all VMs be required > to be shut down for a cluster upgrade. It's not a question of a solution or a fix. This is an inherent property of using a "cluster level" to define a per-release set of features and functionalities applicable to VMs running in such a cluster > In many (most?) real-world clusters > it is neither operationally nor politically feasible to shut down all VMs in > the cluster at the same time! Right, and for that a bug 1348907 was implemented. It's not a perfect fix but unfortunately it's the best we can do in 3.6 as the proper way (to support VMs with different set of features within the same cluster) is missing infrastructure to do that. It will be possible from 4.0 onwards. > Further, it wouldn't work as a solution > anyway; the HE VM _can't_ be shut down and have the cluster still be in a > state where you could change the CV (outside of manually manipulating the DB > directly). Please reconsider this! Bug 1351533 is specifically about Hosted Engine > > Thanks, > Carl (In reply to Marina from comment #0) > > Right now I didn't find anywhere where we mention that cluster compatibility > mode should be changed at all. We should mention it and we should mention it is described in https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Virtualization/3.6/html/Upgrade_Guide/chap-Post-Upgrade_Tasks.html#Changing_the_Cluster_Compatibility_Version but without going into much details about what it actually means, that you e.g. can't resume your snapshots with memory done in previous CL, etc. *** This bug has been marked as a duplicate of bug 1348907 *** |