Data distribution within the UK

This information is for ATLAS UK sysadmins.

ATLAS space tokens and data placement shares have been reviewed for all UK sites. The minimum token size required for ATLAS DATADISK and MCDISK tokens is now 50TB compared to the previous threshold of 25TB. The increased threshold is to alleviate pressure on ATLAS operations when dealing with many small sites.

Some smaller sites are now below the threshold and their share has been reduced to 0%. Sites can increase their share by deploying more disk or re-deploying space tokens. eg. re-deploy DATADISK into MCDISK. Sites should email atlas-support-cloud-uk@cern.ch for advice on how to deploy new disk and how to tweak current token sizes.

This will not affect the number of jobs running at each site as DATA and MC are equally popular. Existing data will remain on all sites until cleaned by ATLAS deletion policy. Regular revision of data share will reflect deployed disk and we expect most sites to increase their storage volume over the coming months, in line with GridPP pledges. A summary of UK site storage and pledge status can be found here.

http://atladcops.cern.ch:8000/drmon/crmon_TiersInfo.html
http://atladcops.cern.ch:8000/drmon/mcmon_TiersInfo.html