[SGVLUG] FC3 and sata

[Michael Proctor-Smith]

On 3/1/06, Emerson, Tom <Tom.Emerson at wbconsultant.com> wrote:
> > -----Original Message-----
> > Behalf Of Claude Felizardo
> > On 3/1/06, matti <mathew_2000 at yahoo.com> wrote:
> > > Q: Anyone with experiences using FC3 and Sata?
> >
> > No direct experience but I suspect a simple setup with SATA would
> > work.  A buddy of mine was trying to install Linspire on a windoze box
> > with dual SATA drives in a RAID-0 configuration.  The Linspire install
> > warned him that RAID-0 on SATA wasn't supported but he thought he'd be
> > okay since he was installing onto an IDE partition.
>
> Likewise, as I run SuSE instead of Redhat, I cannot say for certain, but I do have a recent (and surprising) experience to report.
>
> My main system at home has multiple SATA drives and regular ATAPI/IDE drives.  The SATA drives are striped and essentially 100% devoted to use within Linux; the IDE drives host windows XP using ntfs.  The system currently has SuSE 9.3 on it which installed without any problems.  Last weekend I was about to update to 10.0 and that's when I got an installation warning that the system was "reporting" a hardware/sata raid that was in reality a software raid and that this WAS supported in 2.4 (for /some/ interface boards), but NOT supported in 2.6!

>
> (needless to say, I decided against the upgrade for now...)
>
> I'm fairly certain the 9.x series of Suse is on the 2.6 kernel, hence I'm somewhat surprised to see that message, and even MORE surprised to learn that functionality has been REMOVED in later releases, but as I am using this as an entirely-linux-supported raid (well, jabod is more accurate...) I'm fairly certain things will go well [but I'm scheduling a full backup just to be certain...]
>
>

The problem is that hardware manufacturers lie when they sell
chipsets. They call it hardware raid when in fact it is software raid
or hardware assisted software raid. This works in the windows world
because they write the drivers, which make it look to the OS as if it
is hardware raid. When in fact most if not all the work is done in
software (the manufacturer provided windows driver). There are also
sometimes bios setting like sata or raid this changes how linux will
detect the hardware.

The functionality went away because sometimes the linux software raid
drivers are better then the manufacture "hardware"(read really
software) raid. Plus sata was was unified as part of the scsi
subsystem. It made sense to move sata to scsi from ide subsystem as
the scsi layer already implamented features that would have had to be
added to ide. Like command queueing, hot plugging, and other things
that make sata the equal of scsi in all things but quality of
construction and pure interface speed.