another newbie question

[Jeffrey Watts]

On Thu, 19 Oct 2000, Tony Hammitt wrote:

> Since the "software" raid is using optimized assembler MMX routines,
> it's not really the same as if the routines were written in some
> high-level language.  The bandwidth to the processor is about an order
> of magnitude faster than the bandwidth to the PCI card, without
> considering that the card may be sharing the bus with a video or
> ethernet card.

I remain unconvinced.  I'd like to see some actual benchmarks before
changing my opinion, but I am intrigued.

> About RAID:  Does anyone ever use raid-4 (parity on one drive)?  I'm a
> big fan of raid-1+0 (mirrored stripe set) which is really fast for
> reading since each mirror can be reading different data.  "Raid-6" is
> trying to become a specification; it uses redundant parity so you can
> lose two drives and not lose any data.

Some folks use RAID 4, but not many.  Here at Sprint we use mostly RAID
1+0 and some RAID 5.

My machines actually use RAID 1+0+0 -- hardware mirror, hardware stripe,
software stripe.  We do it since we have multiple FibreChannel enclosures
(1.5TB per cluster).

Good luck,
J.

o-----------------------------------o
| Jeffrey Watts                     |
| watts at jayhawks.net         o-----------------------------------------o
| Systems Programmer         | "I had a linguistics professor who      |
| Network Systems Management |  said that it's man's ability to use    |
| Sprint Communications      |  language that makes him the dominant   |
o----------------------------|  species on the planet.  That may be.   |
                             |  But I think there's one other thing    |
                             |  that separates us from animals.  We    |
                             |  aren't afraid of vacuum cleaners."     |
                             |  -- Jeff Stilson                        |
                             o-----------------------------------------o