Re: [Engine-devel] [node-devel] Support for stateless nodes
On 22/02/12 16:57, Mike Burns wrote:
There has been a lot of interest in being able to run stateless
Nodes
with ovirt-engine. ovirt-node has designed a way [1] to achieve this on
the node side, but we need input from the engine and vdsm teams to see
if we're missing some requirement or if there needs to be changes on the
engine/vdsm side to achieve this.
As it currently stands, every time you reboot an ovirt-node that is
stateless, it would require manually removing the host in engine, then
re-registering/approving it again in engine.
Any thoughts, concerns, input on how to solve this?
Thanks
Mike
[1] http://ovirt.org/wiki/Node_Stateless
Some points need to be considered;
- Installation issues
* Just stating the obvious, which is users need
to remove-add the host on every reboot. This will
not make this feature a lovable one from user's point of view.
* During initial boot, vdsm-reg configures the networking
and creates a management network bridge. This is a very
delicate process which may fail due to networking issues
such as resolution, routing, etc. So re-doing this on
every boot increases the chances of loosing a node due
to network problems.
* CA pollution; generating a certificate on each reboot
for each node will create a huge number of certificates
in the engine side, which eventually may damage the CA.
(Unsure if there's a limitation to certificates number,
but having hundreds of junk cert's can't be good).
* Today there's a supported flow that for nodes with
password, the user is allowed to use the "add host"
scenario. For stateless, it means re-configuring a password
on every boot...
- Other issues
* Local storage; so far we were able to define a local
storage in ovirt node. Stateless will block this ability.
* Node upgrade; currently it's possible to upgrade a node
from the engine. In stateless it will error, since no where
to d/l the iso file to.
* Collecting information; core dumps and logging may not
be available due to lack of space? Or will it cause kernel
panic if all space is consumed?
--
/d
"Hi, my name is Any Key. Please don't hit me!"