Advanced Hardware Advanced Hardware Fundamentals for Fundamentals for

ServersServers

Network ServersNetwork Servers

Servers can be any sizeServers can be any size Normally determined by number and Normally determined by number and

type of hard drives or processors.type of hard drives or processors. What makes a Network Server is the What makes a Network Server is the

software.software.• Windows 2003 ServerWindows 2003 Server• Novell NetwareNovell Netware• LinuxLinux

Services Provided by ServersServices Provided by Servers

Centralized security and login Centralized security and login verificationverification

Centralized backup and other utilitiesCentralized backup and other utilities Shared Storage AreasShared Storage Areas Shared ApplicationsShared Applications Communication between connected Communication between connected

workstationsworkstations

RAIDRAID

Redundant Array of Independent Redundant Array of Independent (or Inexpensive) Disks.(or Inexpensive) Disks.

Provides:Provides:• Performance EnhancementPerformance Enhancement• Data ProtectionData Protection• Combination of BothCombination of Both

Any type of RAID requires multiple Any type of RAID requires multiple physical disk drives.physical disk drives.

RAID ControllersRAID Controllers

HardwareHardware• Controller functionality built into BIOSController functionality built into BIOS• If the motherboard doesn't support If the motherboard doesn't support

RAID, can be added with PCI card.RAID, can be added with PCI card. SoftwareSoftware

• All three NOS's provide for RAID All three NOS's provide for RAID functionality.functionality.

• Software RAID consumes a LOT of Software RAID consumes a LOT of resources, and should be the last choice.resources, and should be the last choice.

Types of RAIDTypes of RAID Raid 0 (Striped Set)Raid 0 (Striped Set)

• Not really RAID because it doesn't Not really RAID because it doesn't provide redundant backup.provide redundant backup.

• Combines two physical drives into one Combines two physical drives into one logical drive to increase performance.logical drive to increase performance.

• Data is written to both drives at the Data is written to both drives at the same time.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 RAIDTypes of RAID

Raid 1 (Mirrored Set)Raid 1 (Mirrored Set)• Provides perfect Fault Tolerance by Provides perfect Fault Tolerance by

copying everything done to a drive onto copying everything done to a drive onto a second drive.a second drive.

• If a drive fails, the other can simply be If a drive fails, the other can simply be inserted in its place.inserted in its place.

• For better Fault Tolerance, mirrored For better Fault Tolerance, mirrored drives should be on different controllers.drives should be on different controllers.

Types of RAIDTypes of RAID

RAID 0/1 (Also called RAID 10)RAID 0/1 (Also called RAID 10)• Combination of performance Combination of performance

enhancement and fault tolerance.enhancement and fault tolerance.• Requires a minimum of 4 disks: 2 disks Requires a minimum of 4 disks: 2 disks

form a striped set, and the other 2 form a striped set, and the other 2 mirror them.mirror them.

Types of RAIDTypes of RAID RAID 5RAID 5

• Uses a more complicated scheme to Uses a more complicated scheme to provide fault tolerance.provide fault tolerance.

• Parity and error correction information is Parity and error correction information is stored on each one of the drives.stored on each one of the drives.

• If any one drive fails, information can be If any one drive fails, information can be rebuilt from the parity information on rebuilt from the parity information on the other drives.the other drives.

• The overhead is the equivalent of one The overhead is the equivalent of one drive.drive.

• Requires a minimum of 3 drives.Requires a minimum of 3 drives.

Other Hardware Considerations Other Hardware Considerations For ServersFor Servers

Most network servers have multiple Most network servers have multiple network cards.network cards.• One to connect to the local network, and One to connect to the local network, and

one to connect to ISP.one to connect to ISP.• The two cards must use the same The two cards must use the same

drivers.drivers.• Manufacturers of commercial grade Manufacturers of commercial grade

cards (Cisco, 3Com) make dual cards, cards (Cisco, 3Com) make dual cards, two NIC's on a single PCI card.two NIC's on a single PCI card.