Site Report: Prague Jiří Chudoba Institute of Physics, Prague WLCG GridKa+T2s Workshop

Grid services 2 independent sites  praguelcg2 (golias) – Tier2 for ATLAS and ALICE  prague_cesnet_lcg2 (skurut) Farm skurut uses old hw 33 dual nodes) and is used mostly for testing. Although its contribution to the Atlas production in the last year achieved a few percent, it will not be considered in the following slides.

Golias farm 250 CPUs as WN (published) mostly HP ProLiant DL 140 2x XEON 3,06 GHz, 2 – 4 GB RAM, 80 GB ATA HDD newer HP blade servers with dual-core Opterons GHz, 4 GB RAM older HP LP1000r 2x PIII 1,13 GHz, 1GB RAM, 18GB SCSI HDD 40 TB (raw) disk space 1 Gbps optical link to CESNET CE, PBSPro, SE: classical + DPM, voboxes (ALICE, ATLAS), LFC (ALICE), BDII gLite installed (only CE is LCG 2.7) supported experiments: LHC (ATLAS, ALICE) – 100 CPUs, D0 – 150 CPUs, AUGER,... manpower: 5 administrators (with many other duties)

Productions during summer 2006 D0 – less activity ATLAS  mostly users’ jobs ALICE  managed by Dagmar Adamova  vobox, 60 – 120 jobs, outputs sent to CERN (xrootd support for DPM planned, current status ???)

Performance Issues PBS server stability often crashed, correlated with a number of jobs in queues (D0 sends thousands of jobs) WN  ALICE RAM requirements, only some nodes can be used one misbehaved job affects other jobs on the same node  ATLAS non-production grid jobs often stucked DPM only a single node, another disk server will be added

Data Transfers, SC4 tests since April ATLAS Tier2’s pretest June 6 – 9  some notes on wiki: ATLAS Tier0 test June – July many performance problems for transfers from CERN to Prague via FZK, succeeded for some datasets

Tier1- Tier2 Data Transfers Problems OK for a few small files does not work for many big files  no improvement since this spring 1 file, 1 GB, done in 65s 50 files (10 in parallel), 1GB each

FTS issues FZK-FZU, FZU-FZK channels replaced by STAR-FZU, STAR-FZK  Tier2’s cannot change settings for uploads to their Tier1 FTS monitoring  we need access to log files, results of other transfers, current status  example from SARA:

Planned activities current ATLAS DQ2 functional test files did not succeeded to reach FZU ATLAS repeated Tier0 test another 2TB of disk space connected to DPM as another pool expected soon local ATLAS data management deletion of old files replication of active files to Tier1 no tools yet