Hi,
This is one of the features lacking in the current tools - the ability to
distinguish different types of storage.
The sites vary from places like CERN and RAL that effectively have unlimited
storage backed up by mass storage systems to small sites that may only have
a few JBOD disks for data needed to improve the efficiency of jobs at that
site.
I think expecting that all sites are happy to take the responsibility of
permanently storing critical experimental data is naïve but that is what the
current model has signed us up to.
Yours,
Chris.
> -----Original Message-----
> From: LHC Computer Grid - Rollout
> [mailto:[log in to unmask]] On Behalf Of Oxana Smirnova
> Sent: 14 January 2005 12:47
> To: [log in to unmask]
> Subject: [LCG-ROLLOUT] IMPORTANT: clarifying purpose of
> Storage Elements etc
>
> Dear sysadmins,
>
> as several people pointed out, there is lack of understanding why do
> experiments use Grid. And since sysadmins are not members of all the
> experiment-specific mailing lists, they have little chance of learning
> it. I feel like I have to clarify several points:
>
> 1. Mailing lists are typically opened for posting only by the members,
> to protect it from SPAM. So please *join* [log in to unmask] or such
> before posting there.
>
> 2. Experiment representatives do not usually read LCG-ROLLOUT mailing
> list, because it is expected to deal with, well, LCG rollout.
>
> 3. Experiments do run in a production mode. The recent LCG
> review stated
> that the LCG is far from being in a production state, but I'd like to
> see it proven wrong. So please don't be surprised to see
> files arranged
> "as if they run production". It's not "if", they *DO* run production,
> and each bit of data is needed in long term (months and years).
>
> 4. Experiments perceive Storage Elements as *STORAGE* elements. They
> expect the files to stay there. And they can not move them elsewhere.
> Please do not advertise your facility as a Storage Element if it is
> *NOT* a Storage Element.
>
> 5. When your Storage Element is full, remove it from the Information
> System, or press the Data Management folks to develop a
> better solution.
> Do not stop PBS queues, as the jobs may well write to another Storage
> Element, not yours.
>
> To summarise, we seem to be asked to move our files from nearly
> everywhere. I guess everybody realizes it's very difficult, and BTW,
> we'll be producing 150% of what we have now in nearest 3
> months. Thus a
> removal of 7% or what won't help. We really expected the storage
> facilities to be such, esp. Tier1-scale centers.
>
> Oxana
>
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