I managed to get this problem by creating a little partition - sda2 in the list below - trying to make use of that 'unused' space. This worked well enough when grub was on a regular partition, but it does not work when setting up /boot and grub on a LVM. The fix was to delete the partition with fdisk and run partprobe.
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 15624191 7811072 83 Linux
/dev/sda2 3 1727 862+ 83 Linux
/dev/sda3 15624192 625142447 304759128 5 Extended
/dev/sda5 15624195 625142447 304759126+ 8e Linux LVM
It would be good for grub to display "there are 3 sectors before the first partition available for core.img, and we need 65" (or whatever the case is) rather than to only say that the core image is large - it's not particularly large.
I managed to get this problem by creating a little partition - sda2 in the list below - trying to make use of that 'unused' space. This worked well enough when grub was on a regular partition, but it does not work when setting up /boot and grub on a LVM. The fix was to delete the partition with fdisk and run partprobe.
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 15624191 7811072 83 Linux
/dev/sda2 3 1727 862+ 83 Linux
/dev/sda3 15624192 625142447 304759128 5 Extended
/dev/sda5 15624195 625142447 304759126+ 8e Linux LVM
It would be good for grub to display "there are 3 sectors before the first partition available for core.img, and we need 65" (or whatever the case is) rather than to only say that the core image is large - it's not particularly large.