From: Harald Finn�s spamcatcher@lantrix.no
Promise is crap with Linux in general, and they really don't support linux at all...
Well, that's because 98% of Promise's products sold are FRAID (Fake/Free RAID). They are a "regular" ATA controller slapped with a 16-bit "trick BIOS." That system has the RAID code needed as long as OS is only accessing 16-bit BIOS Int13h Disk Services.
The second a 32-bit OS loads, it sees the "raw" disks and doesn't understand them. That's where the 100% _software_ driver comes in, it emulates the volume for the 32-bit OS. Since all of that RAID code -- typically licensed from the same company by _all_ of the countless FRAID/mainboard-FRAID vendors out there -- it can't be GPL.
Hence why FRAID products don't have GPL drivers. Except for the 'independent' GPL "ataraid.c" FRAID logic, and the reverse engineered "hptraid.c", "pdcraid" and "silraid.c" companion 'interface' GPL drivers. Of course, there is *0* guarantee those non-vendor implementations will work. I've seen people try to use them and toast their entire volume.
_Real_hardware_ RAID cards completely hide the disks from the system. I.e., the system _never_ talks directly to the hard drives, but an intelligent microcontroller or ASIC. The "RAID Brains" is on the card, and the microcontroller or ASIC actually executes that code -- not your main CPU. The driver is then just a simple block driver to send data to/from the host system to the on-board intelligence.
Hence why the drivers are typically GPL, there's little to them other than a basic, block SCSI driver. No RAID logic is ever exposed in the kernel driver.
-- Bryan J. Smith mailto:b.j.smith@ieee.org
centos-bounces@centos.org wrote on 10.05.2005 22:44:54:
Well, that's because 98% of Promise's products sold are FRAID (Fake/Free RAID).
The card I had in mind was the "real" RAID cards, i.e the SX6000. It was ok while RH8 was the standard and you didn't need to compile a new kernel (ie. you could use the Promise-supplied driver disks). They also had driver source for 2.4 which worked ok as long as you booted from another device and loaded the driver as a module.
And actually, the SX6000 worked with the I2O drivers for a little while with a patch supplied by Alan Cox, but after a few kernel updates I gave up on it.
I was in contact with Promise support about one year ago, and they told me that they had 2.6 drivers in beta, and that they would inform me when it became available. Needless to say, there's still no 2.6 drivers posted on their download pages.
Well, enough bitchin for now... :)
Regards, Harald
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Bryan J. Smith <b.j.smith＠ieee.org> -
Harald Finnås