[ovirt-users] Migration path: All-In-One to self-hosted engine?

[Yedidyah Bar David]

On Tue, Dec 29, 2015 at 3:54 AM, Alan Murrell <lists at murrell.ca> wrote:
> Hi All,
>
> I am just wondering if there is any sort of migration path for those running
> All-In-One setups to a self-hosted engine setup?

I am not aware of anyone trying that.

You can start with [1]. Note that it does not deal with db creation - this is
discussed in [2], but also note that if you use 3.6, you can use the new
'--provision-*' options during restore.

Please carefully read both of them and understand what's to be expected.

Is this a semi-critical system? Or can you easily suffer a few days of downtime?

Do you intend/hope to use the existing storage domain? Note that hosted-engine
does not (currently?) support local storage - it requires some shared storage,
nfs/iscsi/fc. And also that people ran into locking issues with a loopback nfs
mount. So it seems like the best bet is currently loopback iscsi, which means
you'll have to copy your existing data over there somehow.

A rough plan can thus be something like, assuming you have plenty of disk space:
1. shutdown all VMs
2. create a loopback iscsi export domain and export your VMs there
3. Continue with [1] (and [2])
4. During hosted-engine deploy use a different iscsi data domain for the engine
5. After finishing, attach to that export domain and import your VMs from it

I might be missing some parts, didn't fully think this over.

It will be greatly simplified if you have a separate storage server.

[1] http://www.ovirt.org/Migrate_to_Hosted_Engine
[2] http://www.ovirt.org/Ovirt-engine-backup
-- 
Didi