> Are you using MBR or GPT? > MBR has 2TiB size limit, so it kind of sounds like your issue. If that's the > case, you have to reinstall on GPT.
No you don't. At least not if you're using the disk exclusively with OpenBSD or you know for sure that any other operating systems that touch it will co-operate. For disks larger than 2 Tb, you can create an fdisk partition spanning the first 2 Tb, then just adjust the bounds within the disklabel to use the whole capacity of the disk. If you don't need to boot from the disk, you could probably get away with not creating fdisk partitions at all, and just creating a disklabel on the raw volume. However, there are various caveats doing this, some of which may not be obvious.
