1. CERN Computer Centre Tier SC4 Planning FZK October 20 th 2005 Harry.Renshall@ CERN.ch

2. Tony.Cass@ CERN.ch 2 See https://uimon.cern.ch/twiki/bin/view/LCG/ServiceChallengeFourProgress  Twiki shows work in progress: –Service Level Definition - what is required –Technical Factors - components, capacity and constraints –LCG Service Co-ordination Meeting Status –The set of activites required to deliver the building blocks on which SC4 can be built  Leads to our (evolving) hardware configurations for grid servers, operational procedures and staffing  Hope it will prove useful to other sites

3. Tony.Cass@ CERN.ch 3 Using existing buildings  Physical location –B513 »Main Computer Room, ~1,500m 2 & 1.5kW/m 2, built for mainframes in 1970, upgraded for LHC PC clusters 2003-2005. »Second ~1,200m 2 room created in the basement in 2003 as additional space for LHC clusters and to allow ongoing operations during the main room upgrade. Cooling limited to 500W/m 2. »Contains half of tape robotics (less heat/m2). –Tape Robot building ~50m from B513 »Constructed in 2001 to avoid loss of all CERN data due to an incident in B513. Contains half of tape robotics.

4. Tony.Cass@ CERN.ch 4 Capacity today  2000 KSi2K batch – 1100 worker nodes –Adding 2000 KSi2K December  10 STK tape silos of 6000 slots –5 interconnected silos each in two separate buildings –Physics data split –About half of slots now occupied (after media migration) –50 9940B tape drives – 30 MB/sec –200GB capacity cartridges – 6PB total  About 2 PB raw disk storage – older servers used mirrored, newer as raid.

5. Tony.Cass@ CERN.ch 5  Activities »Physics computing services u Interactive cluster - lxplus u Batch computing - lxbatch u Data recording, storage and management u Grid computing infrastructure »Laboratory computing infrastructure u Campus networks—general purpose and technical u Home directory, email & web servers (10k+ users) u Administrative computing servers

6. Tony.Cass@ CERN.ch 6 Physics Computing Requirements  25,000k SI2K in 2008, rising to 56,000k in 2010 –2,500-3,000 boxes (multicore, blade … ?) –500kW-600kW @ 200W/box.  2.5MW @ 0.1W/SI2K  6,800TB online disk in 2008, 11,800TB in 2010 –1,200-1,500 boxes, –600kW-750kW  15PB of data per year –30,000 500GB cartridges/year –Five 6,000 slot robots/year  Sustained data recording at up to 2GB/s –Over 250 tape drives and associated servers

7. Tony.Cass@ CERN.ch 7 Tape plans  By end 2005 we will have 40 high-duty-cycle new model tape drives and matching robotics from each of IBM (3592B) and another vendor for evaluation.  Drive data rates are expected to approach 100MB/sec  Cartridge sizes are expected to approach 500GB  Cartridge costs canonical US$120 so about 25cts/GB (compared with 60 cts/GB today).  For LHC startup operations we plan on 200 drives with these characteristics.

8. Tony.Cass@ CERN.ch 8 Grid operations servers  Hardware matched to QoS requirements – today mostly on ad-hoc older disk servers/farm PCs –Migrate immediately critical/high services to more reliable but simple mid-range servers –Evaluate high availibility solutions to be deployed by SC4 startup looking at: »FC San multiple host/disk interconnects »HA linux (automatic failover) »Logical volume replication »Application level replication »Ready to go spare hardware for less critical services (with simple operational procedures) –Objective to reach availability levels 24 by 7.

9. Tony.Cass@ CERN.ch 9 Mid-range server building block Dual 2.8GHz Xeon, 2GB mem, 4 hot-swap 250GB disks

10. Tony.Cass@ CERN.ch 10 Mid-range server - back  Dual gigabit ethernet, dual power supply

11. Tony.Cass@ CERN.ch 11 Mid-range server burnin test racks  2 different vendors

12. Tony.Cass@ CERN.ch 12 Building 513 ground floor  Space for more…

13. Tony.Cass@ CERN.ch 13 Current Oracle RAC cluster building blocks  Fibre-channel disks/switches infrastructure

14. Tony.Cass@ CERN.ch 14 Oracle RAC cluster  SATA2 FC attached disks and Qlogic switches

15. Tony.Cass@ CERN.ch 15 Oracle RAC cluster - back  Qlogic HBAs in mid-range servers

16. Tony.Cass@ CERN.ch 16 Oracle RAC cluster  Dual FC switch connections

17. Tony.Cass@ CERN.ch 17 Who –Contract Shift Operators: 1 person 24x7 –Technician level System Administration Team »10 team members plus 3 people for machine room operations plus engineer level manager. 24 by 7 on-call. –Engineer level teams for Physics computing »System & Hardware support: approx 10FTE »Service support: approx 10FTE »ELFms software: 3FTE plus students and collaborators. u ~30FTE-years total investment since 2001