Software raid has it's advantages because it is cheap and the raid array is no longer controller dependent. As long as you can reinstall the operating system that made it, you should be able to access the raid array. The main con is lower performance than hardware raid and you probably won't be able to boot from a software raid array.
Hardware raid is bootable, faster and, arguably, more reliable. However if the raid controller croaks you don't have a spare card you will find yourself screwed, stewed and tattooed. Perhaps a more likely scenario is a system with an onboard raid controller and the motherboard fails or needs to be upgraded. Hardware raid can be costly especially when you do the right thing and buy a spare controller from the get go. There is the pseudo hardware raid often found on the enthusiast motherboards. These are the silicon image, highpoint, and promise controllers. The kind of cards where you get 4 port raid-5 for $45. These are the worst because they have disadvantages of both software and hardware raid arrays. The lower performance, cpu cycle consuming, software based raid control with the added dependence on a piece of hardware. I'd definately take a 3ware or Areca raid controller over a software raid array but to say software raid is without merits isn't true. I could sleep soundly at night as long as I knew I had a decent UPS on my server and a good backup routine. -Tharin O.
