Server Systems Administration

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Server Systems Administration
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Types of Servers

• Small Servers
• Usually are PCs
• Need a PC Server Operating System (SOS) such as
  Microsoft Windows Server, Novell NetWare, LINUX
• Large Servers
• Usually use Workstation Servers
• Usually run UNIX

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Symmetric Multiprocessing (SMP)

• PC or workstation can have multiple
  microprocessors
• Work is shared among the microprocessors through
  symmetric multiprocessing (SMP) to increase
  overall speed
• However, if you have N microprocessors, your
  server is not N times faster than a
  single-microprocessor server because of problems
  in assigning work evenly

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RAID

• Redundant Array or Inexpensive (or Independent)
  Drives
• RAID controller controls multiple small
  inexpensive disk drives
• Reads and writes in parallel for higher speed
  despite low-cost drives

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RAID

• Redundant Array or Inexpensive (or Independent)
  Drives
• Information is stored redundantly
• If one disk fails, lose no information
• Drives may even be hot-swappable
• Do not have to turn off computer to replace

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Server Farms

• In large sites, one server is not enough
• Have several, even hundreds of servers
• Called a server farm
• Many PC servers may be more cost-effective than
  fewer workstation servers

Server Farm
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Server Farms

• Load Balancing Approach
• Router or other device sends requests to servers
  based on load

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Server Farms

• Server Clustering Approach
• Act as a single server without an external load
  balancer

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Server Farms

• Reliability
• If one servers hardware fails, operation
  continues without interruption
• However, software failures often take down all
  servers simultaneously

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Server Configuration

• When Server Operating System is Installed, it
  Must be Configured
• Complex task with many steps, many of which
  require you to have conceptual knowledge
• Requires training
• Valuable skill

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Ongoing Work

• Server Systems Administration is Labor-Intensive
  on a Continuing Basis
• Assigning and changing rights for users
• Backup