[Users] Is there a way to force remove a host?
Itamar Heim
iheim at redhat.com
Tue Sep 25 10:34:27 UTC 2012
On 09/25/2012 12:32 PM, Shireesh Anjal wrote:
> On Tuesday 25 September 2012 01:42 PM, Itamar Heim wrote:
>> On 09/25/2012 09:44 AM, Shireesh Anjal wrote:
>>> On Tuesday 25 September 2012 03:25 AM, Itamar Heim wrote:
>>>> On 09/24/2012 11:53 PM, Jason Brooks wrote:
>>>>> On Mon 24 Sep 2012 01:24:44 PM PDT, Itamar Heim wrote:
>>>>>> On 09/24/2012 08:49 PM, Dominic Kaiser wrote:
>>>>>>> This conversation is fine but if I want to force remove no matter
>>>>>>> what I
>>>>>>> should be able to from the GUI. The nodes are no longer available I
>>>>>>> want to get rid of them ovirt does not let me. I can delete from
>>>>>>> database but why not from the GUI? I am sure others may run into
>>>>>>> this
>>>>>>> problem as well.
>>>>>>
>>>>>> what happens to the status of the host when you right click on the
>>>>>> host and specify you confirm it was shutdown?
>>>>>
>>>>> I'm having this same issue. Confirming the host is shut down doesn't
>>>>> make a difference.
>>>>>
>>>>> I'm seeing lots of "Failed to GlusterHostRemoveVDS, error = Unexpected
>>>>> exception" errors in my engine log that seem to correspond w/ the
>>>>> failed
>>>>> remove host attempts.
>>>>
>>>> is cluster defined as gluster as well?
>>>> what is the status of the host after you confirm shutdown?
>>>> any error on log on this specific command?
>>>>
>>>> shireesh - not sure if relevant to this flow, but need to make sure
>>>> removing a host from the engine isn't blocked on gluster needing to
>>>> remove it from the gluster cluster if the host is not available any
>>>> more, or last host in gluster cluster?
>>>
>>> Yes, currently the system tries the 'gluster peer detach <hostname>'
>>> command when trying to remove a server, which fails if the server is
>>> unavailable. This can be enhanced to show the error to user and then
>>> allow 'force remove' which can use the 'gluster peer detach <hostname>
>>> *force*' command that forcefully removes the server from the cluster,
>>> even if it is not available or has bricks on it.
>>
>> what if it is the last server in the cluster?
>> what if there is another server in the cluster but no communication to
>> it as well?
>
> A quick look at code tells me that in case of virt, we don't allow
> removing a host if it has VM(s) in it (even if the host is currently
> not available) i.e. vdsDynamic.getvm_count() > 0. Please correct me if
> I'm wrong. If that's correct, and if we want to keep it consistent for
> gluster as well, then we should not allow removing a host if it has
> gluster volume(s) in it. This is how it behaves in case of 'last server
> in cluster' today.
true, but user can fence the host or confirm shutdown manually, which
will release all resources on it, then it can be removed.
>
> In case of no up server available in the cluster, we can show the error
> and provide a 'force' option that will just remove it from the engine DB
> and will not attempt gluster peer detach.
something like that.
i assume the gluster storage will handle this somehow?
>
>>
>>>
>>>>
>>>>>
>>>>>
>>>>>>
>>>>>>>
>>>>>>> Dominic
>>>>>>>
>>>>>>> On Sep 22, 2012 4:19 PM, "Eli Mesika" <emesika at redhat.com
>>>>>>> <mailto:emesika at redhat.com>> wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> ----- Original Message -----
>>>>>>> > From: "Douglas Landgraf" <dougsland at redhat.com
>>>>>>> <mailto:dougsland at redhat.com>>
>>>>>>> > To: "Dominic Kaiser" <dominic at bostonvineyard.org
>>>>>>> <mailto:dominic at bostonvineyard.org>>
>>>>>>> > Cc: "Eli Mesika" <emesika at redhat.com
>>>>>>> <mailto:emesika at redhat.com>>, users at ovirt.org
>>>>>>> <mailto:users at ovirt.org>, "Robert Middleswarth"
>>>>>>> <robert at middleswarth.net <mailto:robert at middleswarth.net>>
>>>>>>> > Sent: Friday, September 21, 2012 8:12:27 PM
>>>>>>> > Subject: Re: [Users] Is there a way to force remove a host?
>>>>>>> >
>>>>>>> > Hi Dominic,
>>>>>>> >
>>>>>>> > On 09/20/2012 12:11 PM, Dominic Kaiser wrote:
>>>>>>> > > Sorry I did not explain.
>>>>>>> > >
>>>>>>> > > I had tried to remove the host and had not luck
>>>>>>> troubleshooting it.
>>>>>>> > > I
>>>>>>> > > then had removed it and used it for a storage unit
>>>>>>> reinstalling
>>>>>>> > > fedora
>>>>>>> > > 17. I foolishly thought that I could just remove the host
>>>>>>> > > manually.
>>>>>>> > > It physically is not there. (My fault I know) Is there a
>>>>>>> way that
>>>>>>> > > you know of to remove a host brute force.
>>>>>>> > >
>>>>>>> > > dk
>>>>>>> >
>>>>>>> > Fell free to try the below script (not part of official
>>>>>>> project) for
>>>>>>> > brute force:
>>>>>>> >
>>>>>>> > (from the engine side)
>>>>>>> > # yum install python-psycopg2 -y
>>>>>>> > # wget
>>>>>>> >
>>>>>>>
>>>>>>> https://raw.github.com/dougsland/misc-rhev/master/engine_force_remove_Host.py
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> > # (edit the file and change the db password)
>>>>>>> > # python ./engine_force_remove_Host.py
>>>>>>>
>>>>>>> Hi , had looked in the Python script you had provided:
>>>>>>> First, I must say that handling the database directly may
>>>>>>> leave DB
>>>>>>> in inconsistent state, therefore, if there is no other
>>>>>>> option, the
>>>>>>> database should be backed up prior to this operation.
>>>>>>> In addition, I do not like the execution of the SQL
>>>>>>> statements in
>>>>>>> the script.
>>>>>>> There is a SP called DeleteVds(v_vds_id UUID) and you should use
>>>>>>> that since it encapsulates all details.
>>>>>>> For example, your script does not handle permission clean-up as
>>>>>>> the
>>>>>>> SP does and therefore leaves garbage in the database.
>>>>>>> In addition, a failure in your script may leave database in
>>>>>>> inconsistent state while the SP is executed in one
>>>>>>> transaction and
>>>>>>> will leave DB consistent.
>>>>>>> So, in short I would prefer in this case that the relevant SP
>>>>>>> will
>>>>>>> do the clean-up since this is the one that is used by the
>>>>>>> code and
>>>>>>> that insures (at least I hope so) , that all related entities
>>>>>>> are
>>>>>>> removed as well.
>>>>>>>
>>>>>>>
>>>>>>> >
>>>>>>> > Thanks
>>>>>>> >
>>>>>>> > --
>>>>>>> > Cheers
>>>>>>> > Douglas
>>>>>>> >
>>>>>>> >
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Users mailing list
>>>>>>> Users at ovirt.org
>>>>>>> http://lists.ovirt.org/mailman/listinfo/users
>>>>>>>
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> Users mailing list
>>>>>> Users at ovirt.org
>>>>>> http://lists.ovirt.org/mailman/listinfo/users
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>>
>>>>> @jasonbrooks
>>>>
>>>>
>>>
>>
>>
>
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