Hi John,
I have declared my storage 'volatile' and I've done so not because I
delete files whenever I feel like but because I don't consider my storage
safe enough to be declared permanent and if something happens I know I've
done my duty warning the experiments in advance. If experiments don't
exploit the glue schema they should. That's why we have an information
system.
cheers
alessandra
On Wed, 5 Oct 2005, Gordon, JC (John) wrote:
> I believe that the general model of PP computing is that in general data
> does not need backing up. Raw data should be copied so there is
> effectively a backup somewhere else in the world and all other data are
> derived, ie can be recreated either by re-processing the raw data or by
> re-running a simulation from the same seeds. This means that there is no
> need for backup for disaster recovery but it doesn't mean that all data
> can be treated as volatile and just thrown away on a whim because this
> creates big problems for the experiments who have to maintain catalogues
> of where they think their data are. Perhaps they should have a more
> fault-tolerant model that has multiple copies of everything and can cope
> with unreliable catalogues but for now they don't.
>
> I think it would be irresponsible of sysadmins (even collectively) to
> define SEs as volatile without making sure experiments are aware of the
> implications and that they are actually taking some action on the value.
>
> John
>
>> -----Original Message-----
>> From: Testbed Support for GridPP member institutes
>> [mailto:[log in to unmask]] On Behalf Of Henry Nebrensky
>> Sent: 05 October 2005 00:38
>> To: [log in to unmask]
>> Subject: Re: Reminder of the next UKI meeting - Wednesday 5th
>> October 11:00-12:00 via VRVS
>>
>>>
>>> 3) In preparation for Service Challenge 4 all sites need to
>>> initiate and progress two main areas: the deployment of an SRM
>>
>> Currently the user data in our (classic)SE is not backed up -
>> hence the "volatile" (This was general LT2 policy at one
>> point). What happens when we go to SRM? (Not sure of the
>> forum for this)
>>
>
--
********************************************
* Dr Alessandra Forti *
* Technical Coordinator - NorthGrid Tier2 *
* http://www.hep.man.ac.uk/u/aforti *
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