specs for speed of RAID?

bscott@ntisys.com bscott at ntisys.com
Tue Nov 19 18:38:00 CST 2002


On Tue, 19 Nov 2002, at 4:04pm, hagan at cih.com wrote:
> [Hardware RAID gives less of a performance benefit if] the expected load
> isn't cpu intense (e.g. file serving).

  Of course.  After all, a hardware RAID controller is nothing more than a
computer dedicated to doing RAID.  If you're talking about, e.g., a NAS
appliance, someone's "hardware RAID" may well be a Linux box internally.

> Of course, you could also run HW raid10, but i would only do that if the
> HW raid controller is faster than what the OS can deliver.

  My point was mainly that is isn't so much what the OS or host can deliver,
but whether the resources doing the delivery will be busy doing other things
(say, running a database).  This is especially relevant during a failure
recovery; software RAID can really start to drag a system down if you're
rebuilding a disk.

  Of course, your point that many systems have power to spare is a good one,
and should be noted.

> Do realize that those solaris guys have been addicted to software raid for
> a long time via veritas and modern x86 machines have a lot more cpu power
> to burn than most (all?) sparcs.

  The SPARCs have much better I/O, though.  Or so I'm told buy my associates
who like Sun hardware.  :-)

-- 
Ben Scott <bscott at ntisys.com>
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