Originally posted by: pacynkaPL
Probably job is already done, but maybe someone will have the same question:
Bringing Resource Group Offline action is causing deactivation of the resource group -> if application controller is configured, application will be shutdown, file systems will be unmounted and volume groups will be varied off. Your resource will be offline.
Unmanage Resource Group option can be used when you don't want to bring your application done. Cluster stops handling and monitoring application/vg/fs. File systems will be mounted, application will be running, PowerHA won't handle any problems. You can choose this option when you want to restart PowerHA services but without maintenance window. This option should be used only if application monitoring and application controller is configured. If you don't have application monitor configured, bringing back resource group online (so PowerHA can manage and monitor RG) can cause application failure or restart as cluster is not aware of application state.
If you don't have application monitor you can plan maintenace window or use move RG to second node. Of course application will be stopped for some time.