Linux boot

Micik · 02-20-2019, 01:50 AM

Hello linux experts,

I'm reading some old stuff regarding boot managers in Linux. The difference between LILO and GRUB.
I have found this and wonder if this still applies today:
When installing the boot loader in the boot sector of a partition (and not the MBR), make sure the partition is within the first 1024 blocks (approx. 8.5 GB), or enable LBA in the BIOS and the boot loader. Otherwise, the boot loader in the MBR might not be able to find the other boot loader.

pan64 · 02-20-2019, 01:58 AM

Need to know where did you find this. Most probably it is not valid any more. But I can't remember when it was changed.

Micik · 02-20-2019, 02:21 AM

I have found it in one Linux script (printed material) for Linux exam. The material is dated year 2005.

jefro · 02-20-2019, 04:12 PM

On older machines this is true. Don't believe it matters anymore.

"make sure the partition is within the first 1024 blocks (approx. 8.5 GB), or enable LBA in the BIOS and the boot loader. Otherwise, the boot loader in the MBR might not be able to find the other boot loader."

smallpond · 02-20-2019, 05:40 PM

Old BIOS code ran in 16-bit real mode, so shortcuts were taken on arithmetic. Modern EFI firmware has no problem.

michaelk · 02-20-2019, 06:06 PM

The original BIOS only had 10 bits available for the cylinder number which means 0-1023.

https://web.archive.org/web/20160914...ze-limits.html