Re: [ovirt-devel] vdsm disabling logical volumes

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