Re: install/53291: GPT prevents installation

[John Nemeth <jnemeth%cue.bc.ca@localhost>]

The following reply was made to PR install/53291; it has been noted by GNATS.

From: John Nemeth <jnemeth%cue.bc.ca@localhost>
To: gnats-bugs%NetBSD.org@localhost, install-manager%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
        netbsd-bugs%netbsd.org@localhost
Cc: 
Subject: Re: install/53291: GPT prevents installation
Date: Wed, 16 May 2018 18:57:03 -0700

 On May 16,  8:30am, martin%NetBSD.org@localhost wrote:
 }
 } >Number:         53291
 } >Synopsis:       GPT prevents installation
 } >Arrival-Date:   Wed May 16 08:30:00 +0000 2018
 } >Originator:     Martin Husemann
 } >Release:        NetBSD 8.0_RC1
 } >Organization:
 } The NetBSD Foundation, Inc.
 } >Environment:
 } System: NetBSD emmas.aprisoft.de 8.0_BETA NetBSD 8.0_BETA (EMMAS) #1: Fri Mar 2 13:16:40 CET 2018 martin%emmas.aprisoft.de@localhost:/var/nbsd/src-8/sys/arch/i386/compile/EMMAS i386
 } Architecture: i386
 } Machine: i386
 } >Description:
 } 
 } Sysinst is unable to install onto a disk that already has a GPT, even if
 } using MBR in full-disk-for-NetBSD mode and creating new partitions.
 } 
 } >How-To-Repeat:
 } 
 } On a scratch machine (or VM), boot into the RC1 installer (e.g. from CD image).
 } Use utility menu to run /bin/sh.
 } 
 } do:
 }   gpt destroy wd0
 }   gpt create wd0
 }   reboot
 } 
 } Boot into the installer again, do a standard installatin with full disk
 } for NetBSD, create new partition, accept all defaults.
 } 
 } After finishing the installer, remove installer medium and try to boot
 } from wd0 - it will fail (no PBR has been written, GPT protective MBR still
 } in place).
 
      Is this possible confustion with a UEFI disk as UEFI doesn't use
 PBRs?  GPT with UEFI and GPT without UEFI use considerably different
 mechanims to boot.
 
 } >Fix:
 } Should happen in sysinst. Manual workaround:
 } 
 } Go to utility, run /bin/sh, then do:
 } 
 }  > dd if=/dev/zero of=/dev/rwd0d count=100
 } 
 } Exit back to sysinst, go to main menu and do the installation.
 } 
 }-- End of excerpt from martin%NetBSD.org@localhost