I would agree with many of your points save one. HW RAID (not including
Promise IDE stuff because that's not a true HW controller in the same sense
that a Compaq SMART Array Controller is) is always going to be faster. There
is no way, for instance, SW RAID could compete with say a 6400 w/256MB Cache
Module. There again, I'm taking the best possible controller. A quad 3Ghz Zeon
system running SW RAID might outperform say a 3200 with little cache, but even
there I'd want to see the test. I would agree, if you didn't have a controller
then that would change the decision making process dramatically. If you have
it, use it; esp. if its a Compaq controller because they are very good
controllers. I don't the Promise IDE controllers would be serious contenders.
<<JAV>>
---------- Original Message -----------
From: John Andersen
On Thursday 02 September 2004 11:38 am, Joe Polk wrote:
That assumes they were slow to start with. And if you upgrade controllers, then you get the benefits that come with the new controller. You should always go HW controlled RAID if possible. The only reasons not too are, 1) you don't have a controller, or 2) there's no driver available (or reliable driver) for your controller.
The words SHOULD ALWAYS qualify as an opinion, and not fact.
I've used hardware controllers in the past, both SCSI and IDE and I prefer software raid.
Facts: Its just as easy to set up, more flexible (can you add ide members into your scsi raid?), just as fast or faster than hardware raid given an adequate platform, Its cheaper, easily replicated, every bit as robust, and the drivers are always there.
IMHO: The only reasons for hardware raid is You have a processor challenged platform (read whimpy or over worked) , OR you have a budget you have to spend, OR it was built into the machine you have anyway. Might as well use it.
Regarding the "given an adequate platform" condition (above) ... If your processor is too busy to handle the minimal additional IO related tasks associated with SWRaid, its probably too limited for your business needs.
-- _____________________________________ John Andersen ------- End of Original Message -------