Timothy Murphy wrote:
Chris Snook wrote:
Bill Davidsen wrote:
The FC8 install seems to assign drive identifiers in some random order
instead of BIOS order. I thought that was fixed back around 2.6.17, but
it certainly isn't the case AFAIK, if I boot the rescue CD I get one set
of assignments (not BIOS order), and if I boot I get another. Needless
to say this makes getting a bootable install nearly impossible.
Device scanning is asynchronous now, and drives may come up in *any*
order, potentially changing even across reboots even with no changes to
software or hardware. This is why we use labels and uuids.
Would that help when installing from CD, as Bill seemed to be asking about?
The installer assigns labels to everything that isn't on LVM, so
everything should mount just fine. If you add stuff to /etc/fstab
post-install that isn't on LVM and isn't labeled, you could have problems.
The only way the installer can screw up without user intervention is if
it misconfigures grub. Since the bios device ordering is guaranteed to
be different from install to normal boot under these circumstances, the
only guaranteed correct way to fix this is to use firmware, bootloaders,
and partition tables that support partition names, as is the case with
EFI supporting GPT. Unfortunately, in the BIOS/MSDOS world, we're stuck
doing ugly hacks (like latefcload, for fibre channel users) or fixing it
manually post-install.
The good news is that since BIOSes weren't designed to choose from
thousands of boot devices, their ordering is deterministic, so you only
have to fix the bootloader config once.
There are probably more and better ugly hacks we can do to make this
suck less, but fundamentally this is a limitation of the BIOS.
-- Chris
