Re: [Users] Hosted-Engine purpose for gateway check?
On Sun, Apr 6, 2014 at 4:55 PM, Yedidyah Bar David <didi(a)redhat.com> wrote:
----- Original Message -----
> From: "Andrew Lau" <andrew(a)andrewklau.com>
> To: "users" <users(a)ovirt.org>
> Sent: Sunday, April 6, 2014 3:10:19 AM
> Subject: [Users] Hosted-Engine purpose for gateway check?
>
> Hi,
>
> I was recently playing around with the new ovirt 3.4 ga, I'm very
> happy all those issues I reported got fixed :D
>
> I found a new issue regarding the use of PREFIX vs NETMASK which I've
> uploaded here https://bugzilla.redhat.com/show_bug.cgi?id=1084685
>
> Anyway -- I'm wondering what is the purpose for the gateway check in
> the hosted-engine setup? In my test case, I had the following NIC
> configuration
>
> eth0 - public (has gateway)
> eth1 - management
> eth1.1 - storage
> eth2 - vm data (no IP address)
>
> So during the hosted engine install, it will not let me assign eth2 as
> the NIC because it has no IP address or gateway. So I proceed to use
> eth1 instead as, as it has an IP address but again that would fail
> because no gateway. Luckily I have a L3 switch, so I put up a gateway
> for eth1 and that solved that issue.
>
> What is the gateway check supposed to achieve? I also tried to put in
> my eth0's IP address as the gateway but it still failed because of
> those config issues. If management/ovirtmgmt/vmdata are all on a L2
> switch environment, effectively there becomes no gateway and it
> prevents the installation.
It actually does not need to really be a gateway. It's used only as
part of a calculation trying to assess the liveliness of the host.
See [1] for details, especially pages 33-34.
[1] http://www.ovirt.org/images/8/88/Hosted_Engine_Deep_Dive.pdf
--
Didi
I've recall reading that pdf before - however my comments are a little
aimed towards why does the setup require the GATEWAY=x be in the
ifcfg-ethx file when it also asks for the gateway in the otopi setup.
It seems a little redundant and also prevents the ability to proceed
with the setup if you're in a L2 switch environment.
The hosted-engine VM will require a gateway as it only has one nic and
needs to be publicly accessible, so let's say we have:
eth1 -> ovirtmgmt (172.16.0.10) -> hosted-engine (192.168.100.10 w/
192.168.100.1 as gateway)
Isn't 192.168.100.1 the gateway we want to be checking for?
Although now that I think of it, I'm confused where the gateway check
has it's example scenario, is it just for checking to make sure the
hosted-engine will be externally accessible? Wouldn't it also work to
do something like ethtool and check the link exists instead.