[one-users] SCP bottleneck

Luis M. Carril lmcarril at cesga.es
Wed Sep 22 01:52:22 PDT 2010


  Hi,

      Thanks, the scheduling options helps a bit; and we  found a error 
in our configuration too.
      Now is running better.

Cheers

Luis M.

El 21/09/2010 22:15, Ruben S. Montero escribió:
> Hi,
>
> I agree with Stefan, multiple scp's usually will require some tunning
> at the TM level to speed up things. Unfortunately this strongly
> depends on your setup.
>
> A kind of work around (also suggested by Stefan) is to limit the
> number of simultaneous deployments. This can be done with the new
> scheduler with -d option (check [1]). Also take into account that you
> should also adjust -t so the deployment of VM finishes before you
> start the next one...
>
> Cheers
>
> Ruben
>
> [1] http://www.opennebula.org/documentation:rel2.0:schg
>
> On Tue, Sep 21, 2010 at 12:57 PM, Stefan Freitag<stefan.freitag at udo.edu>  wrote:
>> Hi Luis,
>>
>> in Dortmund we have ~250 physical nodes and transfer at the moment the VM
>> (8 GByte per Image) images via SSH to the nodes. Due to the load caused by
>> the SSH transfers we limit the number of VMs deployed in parallel to two.
>> Three or four VMs in parallel should also be possible, but (hopefully) in
>> very near future we will migrate to another setup:
>> then scp-wave will be used in the background to transfer the images to the
>> physical nodes and a "home-brewn" tm mechanism will put in place to start
>> the VMs on the nodes.
>>
>> Cheers
>> Stefan
>>
>>
>> Luis M. Carril schrieb:
>>>    Hello,
>>>
>>>       We've a OpenNebula 2.0 cluster  in SSH mode and when we deploy near
>>> simultaneously 3 or 4 MVs of about 1GB, sometimes some of the
>>> deployments fail because SSH/SCP connection timeouts.
>>>       I've seen in diferent slides that is possible to make TM plugins
>>> based on parallel-ssh or bittorrent.
>>>
>>>       Has anyone experimented similar problems, or developed some of
>>> these plugins?
>>>
>>> Best regards
>>>
>>> --
>>> Luis M. Carril
>>> Técnico Superior
>>> Centro de Supercomputacion de Galicia (CESGA)
>>> Avda. de Vigo s/n
>>> 15706 Santiago de Compostela
>>> SPAIN
>>>
>>> Tel: 34-981569810
>>> lmcarril at cesga.es
>>> www.cesga.es
>>>
>>>
>>> ==================================================================
>>>
>>> _______________________________________________
>>> Users mailing list
>>> Users at lists.opennebula.org
>>> http://lists.opennebula.org/listinfo.cgi/users-opennebula.org
>>>
>>
>> --
>> Dipl.-Inform. Stefan Freitag
>> Institut für Roboterforschung - Abteilung Informationstechnik
>> Universitaet Dortmund         | phone:  +49 (0)231-755-7009
>> Otto-Hahn-Str. 8              | mobile: +49 (0)176-23900074
>> 44221 Dortmund, Germany       | fax:    +49 (0)231-755-3251
>> www.irf.uni-dortmund.de       | email:  stefan.freitag at udo.edu
>>
>> _______________________________________________
>> Users mailing list
>> Users at lists.opennebula.org
>> http://lists.opennebula.org/listinfo.cgi/users-opennebula.org
>>
>
>

-- 
Luis M. Carril
Técnico Superior
Centro de Supercomputacion de Galicia (CESGA)
Avda. de Vigo s/n
15706 Santiago de Compostela
SPAIN

Tel: 34-981569810
lmcarril at cesga.es
www.cesga.es


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