On 22/02/12 18:08, Mike Burns wrote:
On Wed, 2012-02-22 at 17:59 +0200, Doron Fediuck wrote:
On 22/02/12 17:33, Doron Fediuck wrote:
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
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?
One more question / thing to consider; Currently when you manually install a node, you need to configure the management-server's address. Will I need to re-do it on every boot of a stateless node?
As answered in the other response, there are kernel command line parameters to set the management_server. Since this will likely be in a pxe environment, setting the pxe profile to include management_server=<engine_url> should be fine.
I agree it's a valid solution as long as you assume this is relevant for PXE only use case.
Another solution could be to setup a specific DNS SRV record that points to the ovirt-engine and have node automatically query that for the location. This was discussed in the past and for some reason not implemented.
Mike
_______________________________________________ node-devel mailing list node-devel@ovirt.org http://lists.ovirt.org/mailman/listinfo/node-devel
-- /d "Ford," he said, "you're turning into a penguin. Stop it." --Douglas Adams, The Hitchhiker's Guide to the Galaxy