On 2013-07-01, Paul Hartman <paul.hartman+gen...@gmail.com> wrote: > On Mon, Jul 1, 2013 at 4:52 PM, Grant Edwards <grant.b.edwa...@gmail.com> > wrote: >> I've just recently run into a problem where sometimes when a machine >> boots, the kernel can't find init. This appears to be because my grub >> configuration line says "root=/dev/sda5" and _sometimes_ the drive >> that contains my root partition is sdb instead of sda. AFAICT, for the >> past 30 years the linux kernel was 100% consistent in the order that >> hard drives were labelled -- but recently that has seems to have >> changed. > > I wonder if it could be related to parallel initialization of disks.
Apparently so. > I think there's a kernel toggle for that. I'll look into it. >> Are we really expected now to set up an initrd just so that the >> kernel can find the root partition?? > > As far as I know, the answer is "yes". > > FWIW, I always resisted making an initrd until very recently, but > wanted to use UUID in my bootup on my new system. I used this command > (which I re-run whenever I deploy a new kernel): > > dracut -H -o i18n -o resume -o usrmount --force /boot/initramfs.img > > And then added one line to my grub2 config: > > initrd /initramfs.img > > and it just simply works... though it's still a bit of black magic to > me, It's not really that complex. There are two ways to get the kernel to use an initial ram fs as root: the bootloader loads the initial ram image into ram or it gets linked into the kernel when the kernel is built. > and every time I reboot I feel a bit of nervousness when I see > "Loading initial ramdisk..." and don't breathe until it succeeds. :) I've got nothing against initramfs -- on my embedded systems root starts out as an initramfs and stays that way. I just don't see why I should be forced to have one. -- Grant
