Greig A Cowan wrote:
>
> Just to clarify, I don't have a paper on resilient dCache, I was talking
> about sharing an SRM between geographically separate sites.
>
> However, I have just created this page:
>
> http://www.gridpp.ac.uk/wiki/Resilient_dCache
>
> that documents my experiences with resilient dCache over the past couple
> of days. It's only running on a single box with ~25GB of storage so it's
> not exactly at the scale of running across an entire batch farm.
> Unfortunately we don't have spare clusters lying around, but it's a start.
>
> Comments/questions welcome.
Does dCache's SRM check that the box hosting the pool is online
when the SRM answers a query about one of its files? ie is the
issue about not using resilient dCache just that a box/pool
could go offline, or that plus the danger that the SRM will be
falsely claiming to have files that are now offline?
Clearly, having a few percent less storage online than you have
in the racks isn't the end of the world (even if there are files
on them), but _reporting_ that you have files on those inaccessible
disks leads to job failures.
Cheers,
Andrew
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Dr Andrew McNab [log in to unmask] +44-(0)161-275-4227
Co-ordinator of Security Middleware Groups, GridPP & Manchester HEP
GridSite: www.gridsite.org Personal stuff: www.gridlock.org.uk
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