> I want to say that AHCI wasn't introduced until ICH5 or ICH6, but I'm not > totally sure about this.
Sorry, I think you're right there - I really meant "certainly all the recent Intel chipsets support AHCI". However (not being that familiar with it myself) I wouldn't be surprised if AHCI just happens to look really similar to how Intel's SATA support worked on their earlier chipsets ;-) > So, if there is an on-board SATA I/F and AHCI is not in use, what other > cross platform API options are there? To be honest I don't think there are *any* cross platform APIs for SATA, apart from BIOS calls. Think of it like USB1 - there are OHCI and UHCI methods to access the hardware, but if you write a driver for one it won't work with hardware that uses the other. AHCI is just the latest method for accessing SATA controllers, but I think we're still at the stage where the hardware hasn't completely migrated across yet. > It sounds like AHCI may be the right way to go for cross platform support. > I would certainly hope that any server that has no PATA connection on-board, > only SATA, would support AHCI. Long term, AHCI is the way to go. But for the moment I think there are still quite a few machines out there that don't yet support it. >> I take it running your OS inside a VM is not an option? > > We started looking at this a while back, but haven't gotten much done as of > yet. You might want to revisit this, I would think it'd be far easier than writing SATA drivers, and most VMs make disk images available over a PIIX4 IDE controller so your OS should already have solid driver support. > Absolutely... I would certainly think that using BIOS calls for normal I/O > within our O/S would sacrifice considerable performance which we are not > prepared to do. I thought that'd be the case. Unfortunately the BIOS is the only truly cross platform API for accessing disks, but yes, it's not exactly high performance. >> I guess asking your >> customers to set the BIOS to legacy mode would at least give you time to >> figure out a solution. > > If this is available, then yes. As I mentioned earlier, our 2900 doesn't > seem to have this option in our PE's BIOS, which is why I am wanting to make > sure we are headed down the right path with this. If you can't find the option you may find it's already enabled, especially in a server where new hardware like this takes longer to appear. (Don't want customers complaining they can't install Windows NT!) Presumably you could try to boot your OS and see if it can read the disks, that'd tell you pretty quickly. So I guess yes, if you have to write a SATA driver write an AHCI one, just don't expect it to solve all your problems! Cheers, Adam. _______________________________________________ Linux-PowerEdge mailing list [email protected] https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
