USAtlasStorageSetUp - LOCALGROUPDISK in the US

What is LOCALGROUDISK

Each US Tier-2 site hosts a LOCALGROUPDISK area. This space is not pledged to ATLAS and is at the disposal of US ATLAS. The current US allocation of LOCALGROUPDISK is about 700 TB, out of which only 250 TB is currently being used. If LOCALGROUPDISK proves to be a productive resource, future US-ATLAS equipment purchases could increase the LOCALGROUPDISK allocation significantly, at the expense of a corresponding reduction in purchases of unpledged CPU.

For what should LOCALGROUPDISK be used

The RAC encourages the use of LOCALGROUPDISK by US teams and individual users for data that do not meet the criteria for the other ATLAS spacetokens. For example:

1. Physics or performance data for which US groups are responsible but for which ATLAS GROUPDISK space is not available;
2. Data for which SCRATCHDISK provides too short a retention period.

Of course, meeting either of the above criteria is no guarantee that there will be enough LOCALGROUPDISK available.

We encourage you to use of LOCALGROUDISK where it could help your work and so that we can find out:

• which policies (size thresholds, retention times, prioritization ...) we should develop;
• for what activities LOCALGROUPDISK is needed;
• the amount of space that will be needed in the future.

How to use LOCALGROUPDISK

Always use DaTRI to move data to LOCALGROUPDISK.

Requests below a threshhold (currently 2TB total per user) will be approved automatically. Larger requests will be routed via the US Operations Team, and, if necessary to the RAC. You are welcome to send email to usatlas-rac-l@lists.bnl.gov to ask whether a proposed use is appropriate and/or possible.

Monitoring LOCALGROUPDISK usage

Spacetoken allocations and usage in the US, including LOCALGROUPDISK, can be monitored by http://www.usatlas.bnl.gov/dq2/dqsitegroups/getSrmSpace.

Right now http://www.usatlas.bnl.gov/dq2/monitor/findLocalgroupUsage allows you to see who is using the space (and by drilling down, what data they have on LOCALGROUPDISK and at which sites).

The US monitoring is being actively developed - if you can't see what you need, please send an email to usatlas-rac-l@lists.bnl.gov. We also recommend checking this Twiki - we will try to keep it up to date as monitoring evolves.