Power Resiliency

Overview of Power Supply in Data Centers

  • Power is the foundation connecting all technologies.
  • Data centers are engineered to support power needs of computing systems.
  • Considerations must be given to potential power outages.

Power Supply Sources

  • Data centers typically do not generate their own power.
  • Power is supplied by local providers.
  • Data center availability depends on grid stability.

Types of Power Outages

  • Outages can vary in duration, including:
    • Minutes to hours (potentially manageable).
    • Days due to natural disasters (significant disruption).

Uninterruptible Power Supply (UPS)

  • Definition: A UPS (Uninterruptible Power Supply) is a device that provides battery backup when the main power source fails.
  • Purpose: Keeps systems running during blackouts, brownouts (voltage drop), and surges (excessive voltage).
  • **Types of UPS:
    • Offline/Standby UPS:
    • Runs on main power until failure occurs.
    • Internal switch activates battery backup.
    • Line-Interactive UPS:
    • Can adjust voltage slowly during a drop in main power.
    • Especially useful for areas prone to brownouts.
    • Online UPS (Double-Conversion UPS):
    • Continuously uses battery power, eliminating the switch between main and battery power.

UPS Features and Considerations

  • UPS battery capacity is limited; choose one that meets system maintenance needs during outages.
  • Features include:
    • Battery Capacity Options: Varying sizes available depending on needs.
    • Graceful Shutdown Signals: When battery level drops, UPS can signal systems to shut down to prevent corruption.
    • Number of Outlets: Varies per UPS model, affecting the number of devices that can be connected.
    • Suppression Features: Some UPS models include surge suppression for additional protection of connected devices (e.g., for ethernet or telephone lines).

Generators

  • Definition: A generator provides long-term power backup; can operate indefinitely with fuel supply.
  • Generators can:
    • Power an entire building or specific sections.
    • Provide partial power; look for outlets marked as "generator power."

Integration of UPS and Generators

  • Most organizations use both UPS and generators to ensure continuous power:
    • UPS Role: Covers short-term outages and transition period before generator activation.
    • Generator Role: Provides long-term power post-outage; ramp-up required before active power.
    • There is typically a short period (about one minute) without power before the generator fully activates.