SAM

• Business continuity


  Minimizing downtime by identifying potential failures and taking steps to avoid those failures and to reduce their effects
• High availability


  • A system design protocol and associated implementation that ensures a certain degree of operational continuity during a given measurement period
• Fault-tolerant components


  • Disks (use RAID and hot spares)
  • Power supplies (use redundant power supplies)
  • Network cards (use redundant network cards)
• Power supply


  A mechanical device that converts AC power into clean DC power and includes fans for cooling
• Systems that cannot afford to be down should have redundant power supplies
• Error Correcting Code (ECC) memory


  Corrects a single failed bit in a 64-bit block, high-end servers use more expensive ECC memory with special circuitry for testing data accuracy
• NIC teaming


  The process of grouping together two or more physical NICs into one single logical NIC, which can be used for network fault tolerance and increased bandwidth through load balancing
• Computer cluster


  A group of linked computers that work together as one computer, can provide fault tolerance and load balancing
• Most popular forms of clusters

  • Failover clusters
  • Load-balancing clusters
• Failover cluster


  A set of independent computers that work together to increase the availability of services and applications, if one node fails another node begins to provide services
• Active-passive cluster


  Both servers are configured to work as one, but only one at a time is active, the passive node becomes active if the active node goes down
• Active-active cluster


  Designed to provide fault tolerance and load balancing
• Create a failover using Windows Server 2008


  Need two compatible servers with identical hardware, running the same Windows Server 2008 version, in the same domain
• Load-balancing/network load balancing (NLB)


  Multiple computers configured as one virtual server to share the workload
• Uninterruptible Power Supply (UPS)


  An electrical device with batteries to provide backup power during a power outage, ranging from small to large data center units
• Power generator


  A backup electrical system that operates automatically within seconds of a power outage, may be required by building codes for critical systems