[Engine-devel] Migrating an existing installation to hosted engine

Hi all, A message with the same subject was sent to arch around a month ago, see [1]. In short, it suggested two approaches: 1. Use p2v (or v2v) 2. Clean install of OS/engine software and use backup/restore. Following that, I pushed a few changes for engine-backup and engine-setup, with the intention of doing, briefly: 1. hosted-engine --deploy on new host 2. Install OS/software on new vm 3. backup on old engine machine 4. On new vm, do restore, which only restores the database and files, followed by engine-setup, which will fix whatever else needs to be fixed. Some of the changes are still pending, and are under some controversy. See [2], [3], [4]. A more detailed description of the suggested migration path is in [5]. What do you think? Should engine-setup do as little as possible to the system, or as much as needed to save the admin from any manual work? Should engine-setup doing an upgrade do the same as a new setup, or just whatever that's needed to adapt the config/database to the new code? A specific example: if admin chose during initial setup to automatically configure the firewall (iptables/firewalld), should upgrade update it again, or not touch it? Should engine-backup do all these things when doing a restore? Should we have some other utility to do these things? Should we merely document them and let the admin do this manually? [1] http://lists.ovirt.org/pipermail/arch/2013-October/001677.html [2] https://bugzilla.redhat.com/1024707 [3] http://gerrit.ovirt.org/20736 [4] http://gerrit.ovirt.org/20737 [5] http://www.ovirt.org/Migrate_to_Hosted_Engine -- Didi

On Nov 12, 2013, at 12:38 , Yedidyah Bar David <didi@redhat.com> wrote:
Hi all,
A message with the same subject was sent to arch around a month ago, see [1].
In short, it suggested two approaches: 1. Use p2v (or v2v) 2. Clean install of OS/engine software and use backup/restore.
Following that, I pushed a few changes for engine-backup and engine-setup, with the intention of doing, briefly: 1. hosted-engine --deploy on new host 2. Install OS/software on new vm 3. backup on old engine machine 4. On new vm, do restore, which only restores the database and files, followed by engine-setup, which will fix whatever else needs to be fixed.
Some of the changes are still pending, and are under some controversy. See [2], [3], [4].
A more detailed description of the suggested migration path is in [5].
What do you think?
Should engine-setup do as little as possible to the system, or as much as needed to save the admin from any manual work?
Should engine-setup doing an upgrade do the same as a new setup, or just whatever that's needed to adapt the config/database to the new code?
A specific example: if admin chose during initial setup to automatically configure the firewall (iptables/firewalld), should upgrade update it again, or not touch it?
Should engine-backup do all these things when doing a restore?
I think using the same tool for both tasks(backup, migration to hosted engine) has an advantage that you only address issues (like missing item to backup/restore) once and both usecases benefit from a fix
Should we have some other utility to do these things?
Should we merely document them and let the admin do this manually?
[1] http://lists.ovirt.org/pipermail/arch/2013-October/001677.html [2] https://bugzilla.redhat.com/1024707 [3] http://gerrit.ovirt.org/20736 [4] http://gerrit.ovirt.org/20737 [5] http://www.ovirt.org/Migrate_to_Hosted_Engine -- Didi _______________________________________________ Engine-devel mailing list Engine-devel@ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel
participants (2)
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Michal Skrivanek
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Yedidyah Bar David