Pierre Frenkiel wrote: > the problem was with the BIOS boot sequence, and as far as I know, > this is totally independant of any OS. You are correct. The BIOS has an ordering. The OS has an ordering. They are separate software and will each do their own thing. I have often had problems with the BIOS disk ordering being different form the OS disk ordering. And worse is when the BIOS disk ordering is different from the silk screen labeling on the motherboard. The motherboard will have labels for SATA1, SATA2, and so forth but I have had those be completely different from the actual BIOS ordering. In those cases I determined the actual order by experimentation and noted it on the motherboard. In another case a BIOS update changed the BIOS order from the previous version. > the boot sequnce, which was since the installation, several years ago: > > 1 dvd drive > 2 ST3250410AS > > and I found it has been replaced with: > 1 dvd drive > 2 ST3750640AS > > and the problem disappeared, without any change in grub, > as soon as I reverted to the original BIOS boot sequence Yes. Makes sense. > So, my question is still: how can a boot sequence change, without entering > into BIOS at boot. BIOS is software and there are often more bugs in the BIOS seen than in any other part of the system. The BIOS is almost always closed source proprietary and almost never updated. You would need to go very much out of your way to update your BIOS. You could submit this bug to your vendor but how? If you did would they fix it? If they fixed it how long would it take? A year? Would you wait a year for a fix now that you have a workaround? To avoid these problems there is the coreboot project to create free(dom) BIOS software. But as yet I have no hardware capable of running it. I wish I did though. http://www.coreboot.org/ Bob
Attachment:
signature.asc
Description: Digital signature