Aleksander De <aleksander...@kagyu.pl> wrote: > Are there any downsides or potential issues which may happen when > extending boundaries for OpenBSD partition on >2TB disk while using > MBR for booting it at the same time? I need MBR otherwise the machine > will not boot. BIOS/RAID controller does not support UEFI.
The BIOS will use the MBR to identify the bootable partition. Then it will load the PBR sector as code, jump to it, and then load further bootblock code, and kernel after that. It is important to not have the root partition in an earlier part of the disk (I'm being intentionally vague). But our bootcode does not care about the partition limits. What happens is disklabel looks at the MBR partition limits -- when non-MBR partitions (ie disklabel partitions) are being created, usually during install. Beyond that, the MBR size is never looked at again. Where MBR partition limits can matter, is if you go back to disklabel again manually to create partitions. It's splitting the disk up. If you are not careful, you could create overlaps. This mostly happens to people putting multiple operating systems on a machine. Those people need to be careful. Everyone else can ignore this.
