Comments 6 Posted In Red Hat Virtualization Compatibility version - Cluster and Data centre Latest response 2013-07-04T07:23:33+00:00 Will it always be recommended to put hosts in maintenance mode before changing compatibility versions of clusters and data centers?I hope not. pa Started 2013-07-02T13:58:52+00:00 by par.berge Expert 917 points Log in to join the conversation Responses Sort By Oldest Sort By Newest Red Hat Guru 1419 points 2 July 2013 2:12 PM Udayendu Kar Hi Par, Its really not required to put the host into maintenance mode to change the Cluster and DC compatibility. BR, Uday pa Expert 917 points 2 July 2013 2:21 PM par.berge According to: https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Virtualization/3.2/html-single/Administration_Guide/index.html#Changing_the_Cluster_Compatibility_Version I know that's possible to change compatibility without doing the maintenace mode thing. Problem is that I got problem (a known bug) doing so.And the support engineer asked if I had taken the maintenance mode steps. pa Expert 917 points 2 July 2013 2:23 PM par.berge That's why I wonder if this is expected steps in the future upgrades or just a temporary procedure to workaround/minimizing existing problems. ja Guru 1340 points 3 July 2013 7:53 PM janfrode Could you please share a bit about the bug you hit, so that we can evaluate of this is something we should be concerned about when upgrading to v3.2 in a couple of weeks? pa Expert 917 points 4 July 2013 7:17 AM par.berge Sure. The difference is that we went from 3.0 to 3.1. https://access.redhat.com/discussion/boot-failed-not-bootable-disk That is the bug I hit. Will try to locate the BZ. pa Expert 917 points 4 July 2013 7:23 AM par.berge I'm not entirely sure that this bug is related to only changing compatibility version.BZ: https://bugzilla.redhat.com/show_bug.cgi?id=967268 Here is one comment from the support ticket: "Dear Customer. We have the bugreport filled. The issue is happened if cluster compatibility version has been changed without VM shutdown. To classify your issue can you please answer following questions about your infrastructure: 1) Is it upgraded from RHEV 3.1 infrastructure? 2) If yes, did you stop VM while upgrading cluster version? Did you reboot virtual machines after upgrade?"