RAID SUPPORT

RAID SUPPORT

	Raid Support: Description
Version	5.0
Type	Community
Parent Doc	ClarkConnect 5.0 Administration Manual
Next Article	Installation
Previous Article	Compatibility

Overview

Both software and hardware RAID are supported in ClarkConnect. If you plan on implementing hardware RAID, please read the section below regarding supported hardware. Before you decide to purchase an expensive hardware RAID controller card, consider the following passage from the experts at O'Reilly

“Software RAID has unfortunately fallen victim to a FUD (fear, uncertainty, doubt) campaign in the system administrator community. I can’t count the number of system administrators whom I’ve heard completely disparage all forms of software RAID, irrespective of platform. Many of these same people have admittedly not used software RAID in several years, if at all.

Why the stigma? Well, there are a couple of reasons. For one, when software RAID first saw the light of day, computers were still slow and expensive (at least by today’s standards). Offloading a high-performance task like RAID I/O onto a CPU that was likely already heavily overused meant that performing fundamental tasks such as file operations required a tremendous amount of CPU overhead. (…) But today, even multiprocessor systems are both inexpensive and common.”

The rest of the passage is available online in the sample chapter: Managing RAID on Linux from O'Reilly. The book is an excellent resource and highly recommended!

Software RAID

You can implement software RAID in ClarkConnect by selecting the Advanced Partitioning option during the installation wizard and then following the detailed instructions in the Red Hat 9 User Guide:

Hardware RAID

Some hardware RAID controller cards are not true hardware controller cards. They are simple IDE controllers with BIOS and drivers to do software RAID. If redundancy is your primary concern, then software RAID will serve you better than a quasi-hardware RAID card. To quote (again) from the Managing RAID on Linux book from O'Reilly:

“The low-end (RAID) controllers are, in essence, software RAID controllers because they rely on the operating system to handle RAID operations and because they store array configuration information on individual component disk. The real value of the controller is in the extra ATA channels.”

Supported hardware RAID cards: