[Users] [vdsm] Migration failed (previous migrations succeded)

[Michal Skrivanek]

On Feb 3, 2014, at 16:20 , Gianluca Cecchi <gianluca.cecchi at gmail.com> wrote:

> On Mon, Feb 3, 2014 at 1:43 PM, Michal Skrivanek
> <michal.skrivanek at redhat.com> wrote:
>> 
>> On Feb 1, 2014, at 18:25 , Itamar Heim <iheim at redhat.com> wrote:
>> 
>>> On 01/31/2014 09:30 AM, Sven Kieske wrote:
>>>> Hi,
>>>> 
>>>> is there any documentation regarding all
>>>> allowed settings in the vdsm.conf?
>>>> 
>>>> I didn't find anything related in the rhev docs
>>> 
>>> that's a question for vdsm mailing list - cc-ing…
>> 
>> the vdsm.conf has a description for each parameter…just search for all containing "migration":)
>> we do want to expose some/most/all of them in UI/REST eventually, the "migration downtime" setting is there now in 3.4, but others are missing
>> 
>> Thanks,
>> michal
>>> 
>>>> 
>>>> Am 30.01.2014 21:43, schrieb Itamar Heim:
>>>>> On 01/30/2014 10:37 PM, Markus Stockhausen wrote:
>>>>>>>> Von: Itamar Heim [iheim at redhat.com]
>>>>>>>> Gesendet: Donnerstag, 30. Januar 2014 21:25
>>>>>>>> An: Markus Stockhausen; ovirt-users
>>>>>>>> Betreff: Re: [Users] Migration failed (previous migrations succeded)
>>>>>>>> 
>>>>>>>> 
>>>>>>>> Now I' getting serious problems. During the migration the VM was
>>>>>>>> doing a rather slow download at 1,5 MB/s. So the memory changed
>>>>>>>> by 15 MB per 10 seconds. No wonder that a check every 10 seconds
>>>>>>>> was not able to see any progress. Im scared what will happen if I
>>>>>>>> want to migrate a medium loaded system runing a database.
>>>>>>>> 
>>>>>>>> Any tip for a parametrization?
>>>>>>>> 
>>>>>>>> Markus
>>>>>>>> 
>>>>>>> 
>>>>>>> what's the bandwidth? default is up to 30MB/sec, to allow up to 3 VMs to
>>>>>>> migrate on 1Gb without congesting it.
>>>>>>> you could raise that if you have 10GB, or raise the bandwidth cap and
>>>>>>> reduce max number of concurrent VMs, etc.
>>>>>> 
>>>>>> My migration network is IPoIB 10GBit. During our tests only one VM
>>>>>> was migrated.  Bandwidth cap or number of concurrent VMs has not
>>>>>> been changed after default install.
>>>>>> 
>>>>>> Is migration_max_bandwidth in /etc/vdsm/vdsm.conf still the right place?
>>>>> 
>>>>> probably
>>>>> 
>>>>>> And what settings do you suggest?
>>>>> 
> 
> 
> Not tried myself the change of values, but in a previous thread
> (actually for limiting and not speeding up migration ;-) these two
> parameters were described and to be put in each /etc/vdsm/vdsm.conf

yep, they have (brief) description there

> 
> max_outgoing_migrations
> (eg 1 for allowing only one migration at a time)
> 
> migration_max_bandwidth
> (unit is in MBytes/s, vdsm default is 32MiBps and it is for single
> migration, not overall)
> 
> I think it is necessary to follow this workflow for every host

unfortunately yes

> - put host into maintenance
> - stop vdsmd service
> - change values
> - start vdsmd service
> - activate host

> 
> Gianluca