Re: [Rdo-list] introspection and raid configuration

On 05/26/2015 04:42 PM, Imre Farkas wrote: > Hi all, > > I would like to gather some feedback on the current worfklow regarding > the subject. RAID configuration on DRAC machines works as follows (it > assumes there's no RAID volume on the machine): > 1. user defines the deployment profile and the target raid configuration > for each profile > 2. ironic-discoverd introspects the node to gather facts > 3. ach-match picks a deployment profile based on the gathered facts > 4. instack triggers the raid configuration based on the selected profile > > A bug[1] has been discovered regarding step 2: ironic-discoverd fails > because it tries to figure out the size of the local disk but it can't > find any as no volume exists on the RAID controller yet. This is a > chicken-and-egg problem because ironic-discoverd doesn't work if the > RAID volume(s) has not been configured but the RAID configuration can't > be triggered if ironic-discoverd hasn't gathered the facts about the > node. > > Few possible workarounds: > #1: make saving the local disk size optional in the standard plugin in > ironic-discoverd. The downside is that the standard plugin is supposed > to enroll nodes in ironic with all attributes necessary for scheduling. > This assumption might fail with this solution. -1 will never get upstream for the reasons you stated > > #2: run discovery multiple times with different set of plugins. The run > before RAID configuration would exclude the standard plugin while the > run afterwards could potentially exclude others. The parameters passed > by the user to ironic-discoverd for each run need to be properly > documented. It would slow down the installation because each run > requires a reboot which takes a lot of time on bare metal. Possible, but better (IMO) idea below. > > #3: name your suggestion! #3. modify your existing root_device_hint plugin to insert a fake local_gb value (with issuing a warning), and then put it to the beginning of the plugin pipeline. WDYT?

> > Any thoughts/preference on the above described workarounds? > > Thanks, > Imre > > > [1] https://bugzilla.redhat.com/show_bug.cgi?id=1222124