Compaq dc7800 - Convertible Minitower PC User Manual

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Table 4 RAID 5 with 3 hard drives (Parity)
In the previous table, each “Data Segment x” represents a strip. A stripe is made with strip “Data Segment
x”, “Data Segment y” and strip “Parity for x and y.” Notice that the strip “Parity for x and y” is used to
store the required information to recreate the data if any one of the RAID volume members is compro-
mised.
To better illustrate the concept of RAID 5 (parity based RAID), the following figure shows how a sequence
of data “ABCD...” is stored in a RAID 5. In this example, each letter represents a segment or strip. The fig-
ure shows how the various pieces of the information go to different hard drives, hence if any one member
of the RAID 5 fails, the information from all members is not lost.
Figure 4 RAID 5 with three hard drives
First Disk Second Disk Third Disk
Data Segment 1 Data Segment 2 Parity for 1 and 2
Data Segment 3 Parity for 3 and 4 Data Segment 4
Parity for 5 and 6 Data Segment 5 Data Segment 6
Data Segment 7 Data Segment 8 Parity for 7 and 8
Data Segment 9 Parity for 9 and 10 Data Segment 10
Parity for 11 and 12 Data Segment 11 Data Segment 12
Data Segment 13 Data Segment 14 Parity for 13 and 14
Data Segment 15 Parity for 15 and 16 Data Segment 16
Parity for 17 and 18 Data Segment 17 Data Segment 18

Compaq dc7800 - Convertible Minitower PC Specifications

General

Chipset	Intel Q35 Express
Memory	Up to 8 GB DDR2 SDRAM
Form Factor	Convertible Minitower
Processor	Intel Core 2 Duo, Intel Pentium Dual-Core, Intel Celeron
Storage	SATA Hard Disk Drive or Solid State Drive
Graphics	Integrated Intel Graphics Media Accelerator 3100
Optical Drive	DVD-ROM, DVD+/-RW
Networking	Integrated Intel Gigabit Network Connection
Ports	USB 2.0, serial, parallel, VGA, audio in/out, PS/2
Audio	Integrated High Definition Audio
Operating System	Windows XP, Windows Vista
Expansion Slots	1 PCI Express x16, 3 PCI
Power Supply	365W standard efficiency or 80 PLUS power supply