An actual transition strategy and timeline is definitely tied up with the experiment needs and porting progress. I'm keen though to hear if there are any sites other than ECDF where a move sooner rather than later (or later rather than sooner!) is preferred. This is really intended to be sure that if asked I can explain the UK _sites_ position.
Thanks,
Jeremy
On 7 Feb 2013, at 15:38, Alessandra Forti wrote:
> It depends on the experiment. CMS has different executables and needs at the very least separate queues. Atlas uses compatibility libraries and can run SL5 releases on SL6 so it is a bit smoother but they are not ready to go on a big scale. Lhcb are like CMS I think.
>
> All experiments agreed that we can talk again after Moriond.
>
> cheers
> alessandra
>
>
> On 07/02/2013 15:27, Stephen Jones wrote:
>> On 02/07/2013 03:05 PM, Jeremy Coles wrote:
>>> Dear All,
>>>
>>> I would like to understand whether any GridPP sites have a strong need to move their WNs to SL6 and what would the sysadmins on this list consider as a reasonable timeline on which to migrate their WNs to SL6?
>>>
>>
>> Hi Jeremy,
>>
>> We (Liv) don't "need" to move yet. There are some technical issues
>> surrounding the migration, and we might need to do a bit of
>> research.
>>
>> Can a cluster be mixed sl5 and sl6 and run the same jobs, i.e.
>> is it a big bang or an incremental migration?
>>
>> If it's an incremental migration, we can put (say) 4 x WNs on SL6
>> and see how it goes. It's dead easy, and no risk.
>>
>> But if it's a big bang migration, we need more coordination.
>> If we want to be able to rollback, we will need separation, via
>> some scheme (spare CEs, two batch head nodes, two queues,
>> scheduling rules or whatever). We'd make the transition to
>> the new SL6 setup, and gradually retire one set while bringing the
>> other on line. But this will need some careful thinking through
>> to dodge the constraints!
>>
>> Does anyone already have a good plan in their back pocket? Can I see
>> it, please?
>>
>> Steve
>>
>>
>>> Many thanks,
>>> Jeremy
>>
>>
>
>
> --
> Facts aren't facts if they come from the wrong people. (Paul Krugman)
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