[ovirt-users] Change host names/IPs

[Barak Korren]

On 6 October 2016 at 11:27, Davide Ferrari <davide at billymob.com> wrote:
> Well, actually I want to migrate both DNS hostnames and the subnet (from a
> /24 to a /16) to which the ovirtmgr interface is connected.
> The second change is the most problematic as you say..in any case what would
> be the best procedure, even if it implies downtime?

Something like the following (I'm assuming you have multiple hosts...):
1. Put host in to maintenance mode
2. Remove it from oVirt
3. Change host network settings
4. Re-attach host with new setting to oVirt
5. Migrate some VMs to the new host and fix their IP settings
6. Repeat for other hosts

Things to note:
- If you are using hosted-engine, it will further complicate things for you,
  I'm not sure if and how can one change the H.E. IP.
- If you are using an IP-based storage that is accessed via the same subnet,
  you need to ensure it is still accessible with the same name/IP from the
  new subnet.

If you are only making this change so you can run more VMs, you can
consider adding the new subnet as a new VLAN/physical LAN to the
existing hosts, and keep using old /24 subnet for ovirtmgmt. It is a
good idea to separate ovirtmgmt traffic from other traffic anyway...

-- 
Barak Korren
bkorren at redhat.com
RHEV-CI Team