[ovirt-users] Hosted-engine --deploy FQDN questions

Wed Dec 7 11:13:16 UTC 2016

On Wed, Dec 7, 2016 at 12:26 PM, Mark Steckel <mjs at fix.net> wrote:
> Yedidyah - very helpful! Thanks.
>
> A follow-up question re the FQDN for the hosted engine: My understanding is that the FQDN must be resolvable when "hosted-engine --deploy" is executed. However, should the IP that the FQDN resolves to also be assigned/up when "hosted-engine --deploy" is executed?

When deploying the first host, this IP can't be up, as the engine vm
does not exist yet.

And, BTW, it indeed needs to be resolvable, but you can change the address
between this prompt and the actual point where we try to connect to it. So
if you can't control the address (say, you use dhcp, and either do not
control it or do not want to use static reservations), you can do something
like this:

1. Choose a fqdn for the engine, add it to /etc/hosts with a fake address
2. Start deploy
3. When the engine vm is up, and got an IP address, edit /etc/hosts on
the host to point to this address
4. Continue as usual.

No need for this if you do control dhcp - you can choose a MAC address,
add a static reservation for it, and supply it when prompted.

>
>
>
> ----- Yedidyah Bar David <didi at redhat.com> wrote:
>> On Wed, Dec 7, 2016 at 11:36 AM, Mark Steckel <mjs at fix.net> wrote:
>> > Marcin,
>> >
>> > ----- Marcin Mirecki <mmirecki at redhat.com> wrote:
>> >> Mark,
>> >>
>> >> >           Enter the name which will be used to identify this host inside the
>> >> >           Administrator Portal [hosted_engine_1]:
>> >>
>> >> This is the name used for the host inside the Administrator Portal, so basically
>> >> the name of the VM inside the system.
>> >> This does not have to be the hostname, but there are also no objection for it.
>> >>
>> >>
>> >> >           Engine FQDN:  []:
>> >> Yes, you are correct. This must be the FQDN of the host, resolvable to IP.
>> >> This fqdn will be used to access the administration portal.
>> >
>> > If I understand you correctly, both questions apply to the hosted engine vm. Correct?
>>
>> No.
>>
>> The first question is about the host, but not about its address or dns name.
>> It's about the name it will have in the engine, the one you see in the admin ui,
>> in "Hosts", as "Name". After too many questions about this question, we decided
>> to remove it, and in 4.1 it will simply default to the hostname. You'll still be
>> able to set it by manually editing the answer file or passing otopi
>> env, but will
>> not be prompted for it.
>>
>> The second question is indeed about the name that will be used to access
>> the engine vm.
>>
>> Then there is a third item, which we do not ask about: The name that the
>> engine should use to access the host. This is what you see in the admin ui,
>> in "Hostname/IP". This item is determined the following way, for the first
>> host: You are prompted for a NIC to use for the management bridge, we check
>> the IP address of this NIC, then do a reverse-lookup (gethostbyaddr) on this
>> address, and use the result. So you should make sure that this nic has an
>> IP address, that this address has a name (in /etc/hosts or dns), and that
>> this name will also be resolvable and point to the host, when used inside
>> the engine vm (again, by either using dns or manually setting it in
>> /etc/hosts there).
>>
>> >
>> > (If so, I'm glad I asked, because I initially and incorrectly thought that the first question referred to the bare metal machine that hosts the hosted engine vm.)
>>
>> Hopefully the above clarifies this. Please do not hesitate to ask if
>> there are still questions. Also, suggestions for better texts, to make
>> this simpler for the admin, are more than welcome! :-)
>>
>> Best,
>>
>> >
>> > Thanks
>> > Mark
>> >
>> >
>> >
>> >>
>> >> Marcin
>> >>
>> >>
>> >> ----- Original Message -----
>> >> > From: "Mark Steckel" <mjs at fix.net>
>> >> > To: users at ovirt.org
>> >> > Sent: Wednesday, December 7, 2016 6:08:38 AM
>> >> > Subject: [ovirt-users] Hosted-engine --deploy FQDN questions
>> >> >
>> >> > Folks,
>> >> >
>> >> > I'm an OVirt newbie having troubles setting up my first Hosted Engine and am
>> >> > stumbling. In this case I think it may be because of the following two
>> >> > set-up questions.
>> >> >
>> >> >           Enter the name which will be used to identify this host inside the
>> >> >           Administrator Portal [hosted_engine_1]:
>> >> >           Please provide the FQDN for the engine you would like to use.
>> >> >           This needs to match the FQDN that you will use for the engine
>> >> >           installation within the VM.
>> >> >           Note: This will be the FQDN of the VM you are now going to create,
>> >> >           it should not point to the base host or to any other existing
>> >> >           machine.
>> >> >           Engine FQDN:  []:
>> >> >
>> >> > My read of this is that the first question is asking for the name of the
>> >> > host, while the second question is asking for the name (FQDN) of the guest
>> >> > vm which will be the hosted-engine. Is this correct?
>> >> >
>> >> > I'm also presuming that a) the first question should be the hostname of the
>> >> > host, and b) that both the host and guest hostnames should resolve to IP
>> >> > addresses.
>> >> >
>> >> > Thanks
>> >> > Mark
>> >> > _______________________________________________
>> >> > Users mailing list
>> >> > Users at ovirt.org
>> >> > http://lists.ovirt.org/mailman/listinfo/users
>> >> >
>> >
>> > _______________________________________________
>> > Users mailing list
>> > Users at ovirt.org
>> > http://lists.ovirt.org/mailman/listinfo/users
>>
>>
>>
>> --
>> Didi
>

-- 
Didi