Re: [Engine-devel] [node-devel] Support for stateless nodes

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 >>> >>> [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? >> > > 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.

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.

Mike _______________________________________________ node-devel mailing list node-devel(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/node-devel