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143311 (H)
Appendix F – The RAID-Enabled IPC Option
The component most susceptible to shock and vibration in any Industrial PC is the
hard drive. Some sources suggest shock mounting the hard drive; unfortunately,
shock mounting may cause the hard drive to become more vibration-sensitive at
certain frequencies. The most common methods to overcome a susceptibility to
vibration are through the use of either solid-state storage media or redundant hard
drives. Many of Pro-face/Xycom's Heavy-Duty Industrial PCs offer solid-state
media in the form of CompactFlash™ or solid-state hard drives. While many
storage sizes are available, the cost of solid-state drives rises considerably as the
required drive size increases.
A second approach is to use RAID. (RAID stands for Redundant Array of
Independent Disks.) In essence, RAID is two or more hard drives hooked up to the
same controller, either SCSI or IDE. The RAID controller can "stripe" or "mirror"
data. Striping (RAID 0) is used to read and write to many disks at once to increase
hard drive performance, while mirroring (RAID 1) allows the same data to be
available on two or more drives.
There are two methods to implement a RAID solution – via software or dedicated
hardware. Pro-face has chosen a hardware solution because software solutions are
more limited, and require a Windows® 2000 or 2003 Server.
Pro-face’s hardware RAID solution utilizes the Adaptec ATA RAID 1200A, a PCI
IDE
3
RAID controller card. This controller card is installed in the PC, and the
array drives are connected to it, instead of to an IDE controller. Most PCs use an
IDE controller to interface between the system and the hard disks. The RAID
controller occupies a single PCI slot, so you need to verify the available expansion
in your Industrial PC for the application. RAID 1 with two hard drives was chosen
as the optimal solution for creating a more robust, fault-tolerant system in the
Pro-face/Xycom 1507, 3700 Series, and 1600 Series of Heavy-Duty Industrial PCs.
Pro-face has chosen to support Windows® 2000 and Windows® XP for these
RAID-enabled assemblies for optimal and reliable performance.
Note
When installed, the RAID controller bypasses the disk controller on the AIM3
board that runs the disk activity light. Therefore, the disk activity light on the
3700 Series units will not function for the HDDs once the RAID controller is
installed. However, the disk activity light will function for the CD-ROM,
CompactFlash or any X-Bay units, as the RAID controller does not bypass
these items.
In a RAID 1 system, there is a primary and a secondary hard drive. The RAID
controller writes to both drives, but only reads from the primary drive. If the RAID
3
ATA and IDE are used interchangeably in this context. IDE stands for Integrated Drive Electronics; ATA
stands for Advanced Technology Attachment. Both terms refer to the type of controller used in PCs.
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