Promise 20378 SATA controller and FC2 Test1 first impressions ...

[Joe Cooper]

Adam Pearse wrote:
> Well, the good news is that FC2 Test1 does recognize the controller. The 
> down side is it does not support the BIOS created RAID sets defined 
> within Promise's BIOS. I ended up disabling the controller to operate in 
> RAID and have it treat it as IDE (which basically it was anyways). I 
> then setup my two drives using software RAID. Question for anyone who 
> can answer (have has an opinion), will FC2 eventually support the BIOS 
> created RAID images or are we stuck using software RAID and dumb down 
> the controller to basically act as an IDE interface. BTW guys, thanks 
> for your work on getting this out and into our hands.

IMNSHO, unless you're dual booting into Windows on these same disks, you 
probably don't /want/ the BIOS created RAID support.  It is just as much 
software RAID as the Linux software RAID is (i.e. these are not hardware 
RAID controllers with a processor and cache memory on-board), and Linux 
software RAID has more features and can be managed easily using standard 
Linux tools.  Due to the maturity of the Linux RAID software, I would 
expect it to be more fault-resilient than the RAID created by the BIOS, 
as well.

In short...Both are software RAID.  So unless you have a compelling 
reason to use the Promise format of RAID (another OS that requires it), 
there is every reason to use the nicer tools that Linux provides for 
managing RAID.  And as Ken mentioned, the performance of the Linux RAID 
driver is historically better.
-- 
Joe Cooper <joe at swelltech.com>
Web caching appliances and support.
http://www.swelltech.com