Re: [ovirt-devel] vdsm disabling logical volumes

On 05/14/2014 03:02 AM, Jiri Moskovcak wrote: > On 05/14/2014 02:57 AM, Itamar Heim wrote: >> On 05/13/2014 03:16 AM, Jiri Moskovcak wrote: >>> On 05/12/2014 05:27 PM, Dan Kenigsberg wrote: >>>> On Mon, May 12, 2014 at 02:04:05PM +0200, Jiri Moskovcak wrote: >>>> >>>>>>>> Jiri, could you describe why you keep your LV active, but not >>>>>>>> open? >>>>>>>> >>>>>>> >>>>>>> - the setup flow goes approximately like this: >>>>>>> >>>>>>> 1. create the LVs for the hosted-engine >>>>>>> 2. install the engine into the VM >>>>>>> 3. add the host to the engine >>>>>>> - this causes re-deploy of vdsm and deactivating the LVs >>>>>>> 4. start the ha-agent and ha-broker services which uses the LVs >>>>>>> >>>>>>> - I guess we could move the creation of the LVs after the vdsm is >>>>>>> re-deployed, just before the HE services are started, but it won't >>>>>>> fix the problem if the vdsm is restarted >>>>>> >>>>>> It's not going to solve our design problem, but can the users of >>>>>> that LV >>>>>> activate it just before they open it? This way there's only a small >>>>>> window where vdsm can crash, restart, and deactivate the LV. >>>>>> >>>>> >>>>> - no, it runs as vdsm user and as it seems only root can activate LVs >>>>> and >>>>> during the startup when it still has the root privs, it doesn't know >>>>> anything about the storage, the storage is connected on a client >>>>> request >>>>> when it already doesn't have root privs >>>> >>>> Vdsm uses "sudo" for these purposes. >>> >>> - that would solve the problem with privs, but I would really like to >>> avoid the situation where the vdsm disables the LVs as there is no >>> reason for disabling it as there can be situation where vdsm is down >>> and >>> the VM with the engine is still running ok >>> >>>> >>>>> - we could use vdsm to activate the LV if it provides API which >>>>> allows that >>>> >>>> There's the undocumented prepareImage(), but please do not use it >>>> before >>>> an ack by the storage team. >>>> >>> >>> - sure, I'm working on it with Nir now, I won't do anything without the >>> storage team approval ;) >>> >>>> Dan. >>>> >>> >>> _______________________________________________ >>> Devel mailing list >>> Devel(a)ovirt.org >>> http://lists.ovirt.org/mailman/listinfo/devel >> >> I'm missing something here - why doesn't VDSM knows about this LV? its a >> VM started by VDSM? > > - these LVs are created by hosted-engine-setup and are not connected > with the VM for the metadata/config/etc.?