Re: Sysupgrade failing on a system without MBR/GPT (disklabel directly on disk)

Lloyd <[email protected]> Fri, 12 Jun 2026 04:08:44 +0000
Newsgroups gmane.os.openbsd.misc
Message-ID <-mVHHsjQkUAtWPFLDnL2CDwf29tJ2mIWo5Sabuwd0MtXdefYy7yiHW_hk0aqKn1CxM7zRhgxUlFrFAeykWfVO30TLebQb3pxG4ZbhqS-upo=@proton.me>
If this is a VM, create a new (larger) virtual disk, attach to the VM, and
create a proper MBR partition table, then use dd to copy the old disk
contents into the OpenBSD area on the new disk, leaving the MBR intact.

I would do the last part from ramdisk kernel. You may need to re-install
the boot loader onto the new disk.

If you do everything carefully, this method should be non-destructive.

I'm shocked this has worked at all, given the MBR contains the boot code.

Regards
Lloyd

Zeljko Jovanovic wrote:

> This particular server used to be OpenBSD on a SPARC physical machine,
> which was later migrated to x86_64 VM. Probably the image of its original
> disk was just mounted under VM, and x86_64 OS version installed over it.
> In that way, data and configuration files stayed in place.