Re: Kernel 2.4.x SATA Support?
From: Rick Moen (rick_at_linuxmafia.com)
Date: Wed, 08 Sep 2004 00:51:15 GMT
Rohan Beckles <email@example.com> wrote:
> I am in the process of ordering 2 Western Digital 250GB HDs and a
> Highpoint SATA controller. I have a couple of questions:
> 1. Apart from the HighPoint drivers, do I need any other support in
> the kernel?
You don't necessarily need the proprietary drivers from HighPoint
Technologies, Inc.. The standard drivers/ide collection in the Linux
kernel does include HighPoint support. The major advantage (I suppose)
of HighPoint's drivers would be support for their proprietary,
manufacturer-specific software RAID -- "fakeraid", as people say on this
> 2. What is libata? Is it for PATA or SATA? Do I need it?
libata is a driver collection by Jeff Garzik that leverages the kernel's
SCSI layer to make possible high-quality, fast driver support for a
number of SATA chipsets -- not all of them, and not including HighPoint.
> 3. Is it worth getting the HighPoint Rocket 1540 or the Highpoint
> RocketRAID 1540? Does hardware RAID 0 confer enough of an advantage
> over software RAID 0? (see my sig. for hardware)
I wouldn't pay a red cent for HighPoint's proprietary,
manufacturer-specific fakeraid, personally. Others might differ.
> P.S. A question for Rick Moen. You say you are a SCSI bigot - join
> the club!!
(Not a complaint, but: If I remember the thread properly, I was merely
saying that I'm not the right person to ask about hdparm-tweaking tips,
because I'm a SCSI bigot.)
> I too much prefer SCSI over IDE - unfortunately the price
> of SCSI drives is extortionate, at least in the U.K. Why are SCSI
> drives so expensive?
Probably the biggest reason, at this point, is that the manufacturers
have reclassified the SCSI portion of the market as a specialty segment,
which means they can get away with charging specialty-item prices. It's
annoying, isn't it?
Other reasons are listed below.
> Also, don't you at least have a "soft spot" for SATA and IEEE1394?
> After all they do use SCSI commands, and isn't Serial SCSI (or is
> that Serially Attached SCSI?) supposed to be an SATA superset? ;-)
I have more than a soft spot for those, and especially for SATA:
They're a stunning advance in every way, especially for desktop
At the same time, just like the PATA design they are in the middle of
replacing, SATA drives don't have automatic mapping-out of bad sectors
using spare tracks by the host adaptor, they are built from assemblies
with the QA pile of 5% rejection rate parts instead of the 1% rejection
rate pile, they have less robust design against heat buildup and
mechanical failure and thus aren't rated for 24x7 operation, and they
achieve acceptable performance only with the assistance of large amounts
of write-back cache RAM on the drive chassis, with potentially
catastrophic effect in the event of power failure or seize-up,
especially on RAID arrays. All of this means there are places where
SATA's use makes sense, and others where it doesn't.
Please see this paper for detail on the risks and drawbacks:
So, use SATA where it makes sense. If you've been happy with PATA
drives, e.g., in your desktop box or laptop, you'll be ecstatic with
SATA, since it's better in every way. Even if you don't today, it's
what you'll be getting in such machines in the future, because PATA's
I have less acquaintance with IEEE1394 (Firewire, iLink) in
performance-sensitive situations, so I won't comment.
-- Cheers, Facta tua Restitueri ad Status Pristinus Eius. Rick Moen (May your data be restored to firstname.lastname@example.org its original pristine condition.)