CIT 470: Advanced Network and System Administration

1. CIT 470: Advanced Network and System Administration Data Centers CIT 470: Advanced Network and System Administration

2. Topics Data Center: A facility for housing a large amount of computer or communications equipment. • Environment • Power • Racks • Blackbox CIT 470: Advanced Network and System Administration

3. Environmental Requirements Temperature: 64-72F (17-22C) Temperature inside case around 40F higher. Chips and hard disks fail around 120F. Humidity 35-65% Too low: static discharges. Too high: water condenses, short circuits. Power Reliable, conditioned power. Physical Security Prevent accidents, hacking, theft, vandalism. CIT 470: Advanced Network and System Administration

4. Environment Features HVAC: Heating, Ventilation, Air Cond UPS: Power conditioning, <1hr battery Generator: For long term power outages. Accessibility: For large equipment. Card Lock: SAs only, records entrances/exits. Fire Suppression System: Not water based. Humidity/Water Detection CIT 470: Advanced Network and System Administration

5. HVAC HVAC systems can fail due to Power loss. Coolant leakage. Mechanical failure. Detect HVAC failures early. Many HVACs have sensors to report failure. Temperature monitor in data center otherwise. HVAC maintenance n+1 redundancy to avoid immediate disaster. Usually handled by external contractor. CIT 470: Advanced Network and System Administration

6. Space Aisles Must be wide enough to move equipment. Hot spots Result from poor air flow. Servers can overheat when avg room temp low. Work space A place for SAs to work on servers. Desk space, tools, etc. Capacity Ensure that you have enough room to grow. CIT 470: Advanced Network and System Administration

7. Power • UPS provides power. • Generator provides auxiliary power. • ATS switches to generator if building power fails. Liebert UPS and battery bank. CIT 470: Advanced Network and System Administration

8. Power Distribution Under floor power • Susceptible to water; requires water sensors. • Overhead power bus is preferrable. Overhead Power Bus • Drop power down to each rack individually. • Don’t run power cords between racks. • Each rack will have its own PDU. CIT 470: Advanced Network and System Administration

9. Power Distribution Units (PDU) • Different power sockets can be on different circuits. • Individual outlet control (pwr cycle.) • Current monitoring and alarms. • Network management (web or SNMP.) APC Power Distribution Unit CIT 470: Advanced Network and System Administration

10. The Power Problem • Servers require much more power today. • Blades allow more servers per square ft. • Upgrades may have to wait for electricity. • Power is a major data center cost • $5.8 billion for server power in 2005. • $3.5 billion for server cooling in 2005. • $20.5 billion for purchasing hardware in 2005. • Google, MS building centers near cheap power. CIT 470: Advanced Network and System Administration

11. Physical Security • Keycard + code to restrict who can access. • Biometrics are becoming popular alternative. • Electronically log all accesses. • Surveillance cameras. • No windows. • No floor/ceiling access. CIT 470: Advanced Network and System Administration

12. Racks • 19” rack standard • EIA-310D • Other standard numbers. • NEBS 21” racks • Telecom equipment. • 2-post or 4-post • 1U = 1.75 in • Air circulation (fans) • Cable management • Doors or open CIT 470: Advanced Network and System Administration

13. Rack Purposes Organize equipment • Increase density with vertical stacking. Cooling • Internal airflow within rack cools servers. • Airflow determined by arrangement of racks. Wiring • Cable guides keep cables within racks. Power infrastructure • PDUs in racks distribute power to servers. CIT 470: Advanced Network and System Administration

14. Buying a Rack Buy the right size • Space for servers. • + space for power, patch panel, etc. Be sure it fits your servers. • Appropriate mounting rails. • Shelves for non-rack mountable servers. Physical/environment security • Locking front and back doors if needed. • Sufficient power and cooling. • Power/environment monitors if needed. CIT 470: Advanced Network and System Administration

15. Wiring It’s important to be neat. • So you can get the cable for the right server. • Label both ends of each cable. Prewiring • Run power, net, serial cables when rack setup. • Greatly reduces time to setup a new server. Hiding messiness isn’t being neat. • Raised floors can hide cables. • Some sites don’t remove old cables to avoid accidentally taking down the wrong server. CIT 470: Advanced Network and System Administration

16. Project Blackbox • Data Center in a shipping container. • Google • Sun • PB of storage. CIT 470: Advanced Network and System Administration

17. References • “19-inch Rack”, http://en.wikipedia.org/wiki/19-inch_rack, 2007. • 42u, “Top 5 Things to Keep in Mind When Buying a 19” Rack,” http://www.42u.com/server-rack-article.htm, 2007. • Mark Burgess, Principles of System and Network Administration, Wiley, 2000. • Data Center Journal, http://www.datacenterjournal.com/, 2007. • “Data Center,” http://en.wikipedia.org/wiki/Data_center, 2007. • Aeleen Frisch, Essential System Administration, 3rd edition, O’Reilly, 2002. • Dan Goodin, “IT confronts the Data Center Power Crisis,” http://www.infoworld.com/article/06/10/06/41FEgreen_1.html, 2006. • Hurgh, “Rack Layout,” http://www.hurgh.org/articles.php?article=rack_layout, 2007. • “Project Blackbox,” http://en.wikipedia.org/wiki/Project_Blackbox, 2007. • Thomas A. Limoncelli and Christine Hogan, The Practice of System and Network Administration, Addison-Wesley, 2002. • Evi Nemeth et al, UNIX System Administration Handbook, 3rd edition, Prentice Hall, 2001. CIT 470: Advanced Network and System Administration