„The square root of serving multiple experiments is a single dCache“

GridKa dCache

CMS ATLAS ALICE LHCb

hepcg wisent textgrid kerndgrid ingrid

astrogridmedigrid

c3grid

9 other D-Grid VOs

com-pass

cdf auger belle ops dteam

D-Grid dCache

c3grid

astrogrid

medigrid

kerndgrid

ingrid

textgrid

wisent

hepcg

GridKa dCacheLHCb CMS compass

ops

cdf

belledteam

auger

ALICE

ATLAS dCacheATLAS ops

Procedure1. Pool migration (hosts only serving ATLAS pools)

2. Installation of new ATLAS administration nodes

3. Complete downtime of original dCache instance

a) dump of SRM and PNFS DB

b) Remove ATLAS configuration:

i. Switch off all ATLAS pools

ii. PoolManager

iii. Pin- and SpaceManager entries

iv. PNFS DBs

c) Restart original dCache instance

4. Reload DB dumps in new ATLAS instance

a) Remove all non ATLAS entries from DBs

b) Change dCacheSetup on all ATLAS pools

5. Start ATLAS instance

Deadlock situation One dteam file located on ATLAS pool PNFS id not known to dCache Pool tried flushing file to tape PnfsManager did not know file PnfsManager run in deadlock situation

Doris.Ressmann@iwr.fzk.deSteinbuch Centre for Computing

Motivation Performance problems – bottleneck SRM, PNFS

Further single points of failure: PoolManager, PinManager

Easier to manage due to less complex configuration

VOs do not disturb each other

Configuration can be fine tuned for the requirements of the separated VO

Further information today:

037 - Improving data distribution on disk pools for dCache

070 - dCache administration at the GridKa Tier-1-center, ready for data taking

069 - Reference installation for the German grid Initiative D-Grid

ATLAS nodes

Head node

PNFS deamon, PnfsManager, postgres DB

SRM,utilityDomain, postgres DB

gPlazma

Billing DB

dCap door

4 gridftp doors

23 pool nodes

Forschungszentrum Karlsruhe GmbH

Hermann-von-Helmholz-Platz 1

D-76344 Eggenstein-Leopoldshafen

D.Ressmann, S.Halstenberg, C.Jung, A.Trunov, J.van Wezel

Separation

9 other D-Grid VOs