Jim Cox wrote: > I recently upgraded a stock Fedore Core 4 kernel on a Sun V20z dual > Opteron box to a 2.6.14-1.1656_FC4smp kernel and was suprised to find > what had been /dev/sda is now identified as /dev/sdb, and vice-versa. > Interestingly, everthing seems to work OK, I guess because GRUB is > working off of disk labels rather than device names (?), but my > question is what gotchas might be waiting for me down the road? I > don't expect to be modifying this setup at all, if that matters. Very nearly. Grub is working with the BIOS to access the disk. It doesn't see Linux's labelling at all: just what the BIOS calls stuff. And the kernel or operating system that you might be about to run doesn't affect that. What grub does do is use BIOS calls to load the kernel and the initrd. The kernel loads itself and the initrd, which contains the modules and the mount command needed to mount the real root. And it's that mount command (and the one in /bin) that can and is set to use mount labels rather than device names. I understand that Fedora is set up this way precisely so it will keep working if the device names change (for example, if the evolution of libata means that what was a /dev/hda becomes a /dev/sda). In other words, this is intended. Any gotchas would count as bugs and should be entered in bugzilla. However, my experience is that there should be none, and this seems to be the experience of quite a few other people. (I should note, though, that mount will have problems if you ever have duplicate labels on the same system. The most common way for this to happen is if you put one computer's drive into another computer. Hope this helps, James. -- E-mail address: james | "Today Has Been Two Of Those Days." @westexe.demon.co.uk | -- Mike Andrews
