Chapter 9 Advanced Hardware Fundamentals for Servers

Network Servers Servers can be any size Servers can be any size Normally determined by number and type of hard drives or processors. Normally determined by number and type of hard drives or processors. What makes a Network Server is the software. What makes a Network Server is the software. Windows 2003 ServerWindows 2003 Server Novell NetwareNovell Netware LinuxLinux

Services Provided by Servers Centralized security and login verification Centralized security and login verification Centralized backup and other utilities Centralized backup and other utilities Shared Storage Areas Shared Storage Areas Shared Applications Shared Applications Communication between connected workstations Communication between connected workstations

RAID Redundant Array of Independent (or Inexpensive) Disks. Redundant Array of Independent (or Inexpensive) Disks. Provides: Provides: Performance EnhancementPerformance Enhancement Data ProtectionData Protection Combination of BothCombination of Both Any type of RAID requires multiple physical disk drives. Any type of RAID requires multiple physical disk drives.

RAID Controllers Hardware Hardware Controller functionality built into BIOSController functionality built into BIOS If the motherboard doesn't support RAID, can be added with PCI card.If the motherboard doesn't support RAID, can be added with PCI card. Software Software All three NOS's provide for RAID functionality.All three NOS's provide for RAID functionality. Software RAID consumes a LOT of resourcesSoftware RAID consumes a LOT of resources

Types of RAID Raid 0 (Striped Set) Raid 0 (Striped Set) Not really RAID because it doesn't provide redundant backup.Not really RAID because it doesn't provide redundant backup. Combines two physical drives into one logical drive to increase performance.Combines two physical drives into one logical drive to increase performance. Data is written to both drives at the same time.Data is written to both drives at the same time. Increases performance 30 to 50%.Increases performance 30 to 50%. If one drive fails, all information is lost.If one drive fails, all information is lost. Requires a minimum of 2 HD.Requires a minimum of 2 HD.

Types of RAID Raid 1 (Mirrored Set) Raid 1 (Mirrored Set) Provides perfect Fault Tolerance by copying everything done to a drive onto a second drive.Provides perfect Fault Tolerance by copying everything done to a drive onto a second drive. If a drive fails, the other can simply be inserted in its place.If a drive fails, the other can simply be inserted in its place. For better Fault Tolerance, mirrored drives should be on different controllers.For better Fault Tolerance, mirrored drives should be on different controllers.

Types of RAID RAID 0/1 (Also called RAID 10) RAID 0/1 (Also called RAID 10) Combination of performance enhancement and fault tolerance.Combination of performance enhancement and fault tolerance. Requires a minimum of 4 disks: 2 disks form a striped set, and the other 2 mirror them.Requires a minimum of 4 disks: 2 disks form a striped set, and the other 2 mirror them.

Types of RAID RAID 5 RAID 5 Uses a more complicated scheme to provide fault tolerance.Uses a more complicated scheme to provide fault tolerance. Parity and error correction information is stored on each one of the drives.Parity and error correction information is stored on each one of the drives. If any one drive fails, information can be rebuilt by the parity information on the other drives.If any one drive fails, information can be rebuilt by the parity information on the other drives. The overhead is the equivalent of one drive.The overhead is the equivalent of one drive. Requires a minimum of 3 drives.Requires a minimum of 3 drives.

Other Hardware Considerations For Servers Most network servers have multiple network cards. Most network servers have multiple network cards. One to connect to the local network, and one to connect to ISP.One to connect to the local network, and one to connect to ISP. The two cards must be identical.The two cards must be identical. Manufacturers of commercial grade cards (Cisco, 3Com) make dual cards, two NIC's on a single PCI card.Manufacturers of commercial grade cards (Cisco, 3Com) make dual cards, two NIC's on a single PCI card.