https://bugzilla.novell.com/show_bug.cgi?id=350573
User drankinatty@suddenlinkmail.com added comment
https://bugzilla.novell.com/show_bug.cgi?id=350573#c12
--- Comment #12 from David Rankin
There are actually three types of RAIDs.
1. h/w RAID - as Dejan described.
2. s/w RAID - mdX, as Dejan described.
3. fake (BIOS) RAID - 99% of [SP]ATA controllers which advertise that they support RAID actually don't have any hardware to support RAID. They are all plain ATA controller which can speak to attached devices as directed by the operating system. The only difference from pure software RAID is that the code stored in the flash chip (BIOS) knows the used RAID format and can boot from RAID.
In that sense, BIOS RAID is purely software too where the BIOS and the operating system use the same software RAID format. Before the OS boots, BIOS runs the RAID code. After the OS boots OS code runs its RAID code - which is dm in Linux.
Fake RAID is usually worse than software RAID. There are several on-disk formats out there, so when you change system configuration you might need to rebuild the array and not all BIOS RAID implementations are of good quality. Unless there's specific reason to use fake RAID (ie. some other OS requires it or whatever), it's always better to use md && grub can boot from md RAID1.
That said, the reported problem doesn't look like a libata or dm problem. I agree with Dejan that most likely cause is misconfigured initrd.
Thanks Tejun, But, what would explain the successful BIOS raid install on the Gigabyte/nVidia board/raidChip and the failure to boot on the MSI/Promise board? I used the same 10.3 DVD for both installs. It worked with the gigabyte board, but failed with the MSI board. Is there a bug related to the MSI/Promise install? My point is that "If it worked with the Gigabyte/nVidia board why did it not work with the MSI/Promise board?" Your BIOS raid/md raid discussion is excellent. I guess my understanding was the entirely separate chip on the board that says "Promise SATA RAID Controller" was supposed to handle the data mirroring through that hardware chip and decrease the load on the OS presented by the software raid. If that isn't true, then what is the purpose of the separate chips on the motherboards that say RAID that are separate and apart from the ATA controller chips that are also present? Another interesting point is the disk performance of the dual Seagate 250s on the Gigabyte/nVidia raid board with the hardware/BIOS raid install far exceeds the performance of the dual Seagate 340s on the MSI/Promise system with md software raid configured. Both are P4 2800 systems with 2G of ram. The response time was measured with "rpm -qa | grep php". The difference is nearly 2:1? *** I don't mind dumping the MSI/Promise install and trying again with BIOS raid and exploring the initrd issue if you think that will help *** Also, I will post the yast logs when I get back to work. Thank you all for looking into this. I just want to help fix whatever did not work on the MSI/Promise board for opensuse and for everyone else that has that setup. -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.