[Users] Migrate cluster 3.3 -> 3.4 hosted on existing hosts

[Yedidyah Bar David]

----- Original Message -----
> From: "Ted Miller" <tmiller at hcjb.org>
> To: "users" <users at ovirt.org>
> Sent: Tuesday, April 1, 2014 10:40:38 PM
> Subject: [Users] Migrate cluster 3.3 -> 3.4 hosted on existing hosts
> 
> Current setup:
> 
> 
>     * 3 identical hosts running on HP GL180 g5 servers
> 
> 
>         * gluster running 5 volumes in replica 3
>     * engine running on VMWare Server on another computer (that computer is
>     NOT available to convert to a host)
> 
> Where I want to end up:
> 
> 
>     * 3 identical hosted-engine hosts running on HP GL180 g5 servers
> 
> 
>         * gluster running 6 volumes in replica 3
> 
> 
>             * new volume will be nfs storage for engine VM
>     * hosted engine in oVirt VM     * as few changes to current setup as
>     possible
> 
> 
> The two pages I found on the wiki are: Hosted Engine Howto and Migrate to
> Hosted Engine . Both were written during the testing process, and have not
> been updated to reflect production status. I don't know if anything in the
> process has changed since they were written.

Basically things remained the same, with some details changing perhaps.

> 
> 
> Process outlined in above two pages (as I understand it):
> 
> 
> 
> 
> have nfs file store ready to hold VM
> 
> Do minimal install (not clear if ovirt node, Centos, or Fedora was used--I am
> Centos-based)

Fedora/Centos/RHEL are supposed to work. ovirt node is currently not
supported - iirc it's planned to be supported soon, not sure.

> # yum install ovirt-hosted-engine-setup
> # hosted-engine --deploy
> 
> 
> Install OS on VM
> 
> 
> return to host console
> 
> 
> at "Please install the engine in the VM" prompt on host
> 
> 
> on VM console
> # yum install ovirt-engine
> 
> 
> on old engine:
> service ovirt-engine stop
> chkconfig ovirt-engine off
> 
> set up dns for new engine
> 
> 
> # engine-backup --mode=backup --file=backup1 --log=backup1.log
> scp backup file to new engine VM
> 
> 
> on new VM:

Please see [1]. Specifically, if you had a local db, you'll first have
to create it yourself.

[1] http://www.ovirt.org/Ovirt-engine-backup#Howto

> # engine-backup --mode=restore --file=backup1 --log=backup1-restore.log
> --change-db-credentials --db-host=didi-lap --db-user=engine --db-password
> --db-name=engine

The above assumes a db was already created and ready to use (access etc)
using the supplied credentials. You'll naturally have to provide your own.

> # engine-setup
> 
> 
> on host:
> run script until: "The system will wait until the VM is down."
> 
> 
> on new VM:
> # reboot
> 
> 
> on Host: finish script
> My questions:
> 
> 1. Is the above still the recommended way to do a hosted-engine install?

Yes.

> 
> 2. Will it blow up at me if I use my existing host (with glusterfs all set
> up, etc) as the starting point, instead of a clean install?

a. Probably yes, for now. I did not hear much about testing such a migration
using an existing host - ovirt or gluster or both. I did not test that myself
either.

If at all possible, you should use a new clean host. Do plan well and test.

Also see discussions on the mailing lists, e.g. this one:

http://lists.ovirt.org/pipermail/users/2014-March/thread.html#22441

Good luck, and please report back!
-- 
Didi