LHC Computer Grid - Rollout
> [mailto:[log in to unmask]] On Behalf Of Oxana Smirnova said:
> 5. When your Storage Element is full, remove it from the Information
> System, or press the Data Management folks to develop a
> better solution.
As Owen said, this is not a good solution because you won't be able to read
the files, the normal replica management tools need to find the SE in the
information system. Also, intrinsically a full SE is not a fatal error any
more than a full disk on any system, it's just that users need some way of
dealing with the condition. The free space is published in the information
system so it should be possible to recognise the situation and deal with it
in whatever way you like - maybe atlas would actually rather leave the SEs
full and write new files somewhere else. The only reason it can be a problem
is on systems where all VOs share the space and there are no quotas, so one
VO can block the others.
A separate point is the question of reliability. Tier-1s will typically
commit to a high level of reliability so you can resonably expect that files
there are safe. Many sites, even ones with large amounts of space, may not
have much reliability or backup, so if disks crash data may be lost. I'm not
sure how that can be represented, how do you quantify the likelihood of
losing data?
Stephen
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