kern/159222: [boot0] unusual behavior writing boot0 from single user mode

[Tim Newsham]

The following reply was made to PR kern/159222; it has been noted by GNATS.

From: Tim Newsham <tim.newsham at gmail.com>
To: Andriy Gapon <avg at freebsd.org>
Cc: bug-followup at freebsd.org
Subject: Re: kern/159222: [boot0] unusual behavior writing boot0 from single
 user mode
Date: Thu, 28 Jul 2011 06:59:12 -1000

 On Thu, Jul 28, 2011 at 5:27 AM, Andriy Gapon <avg at freebsd.org> wrote:
 > I've noticed that you report a problem with performing some disk-related
 > operations, but you haven't provided any information about your disk partitioning
 > and filesystem layout.
 > Also you emphasized that the problem occurs in the single user mode, but it is not
 > immediately clear if you tested the same operations in the multi-user mode.
 
 I believe I got a permission denied error when trying in multi
 user mode.  I assumed it was due to secure level.  I just tried it
 again now and it asked me twice for confirmation and when I
 did reported:
   fdisk: Class not found
   fdisk: Failed to write sector zero
 
 at this point none of the issues I reported in the bug occur.
 
 As for disks, I have tried on two separate systems.  One system was
 created just for this test in vmware and used the .iso installer
 and accepted the default partitioning and slicing offered by the installer.
 I assume there's nothing special about it:
 
 ******* Working on device /dev/da0 *******
 parameters extracted from in-core disklabel are:
 cylinders=1044 heads=255 sectors/track=63 (16065 blks/cyl)
 
 Figures below won't work with BIOS for partitions not in cyl 1
 parameters to be used for BIOS calculations are:
 cylinders=1044 heads=255 sectors/track=63 (16065 blks/cyl)
 
 Media sector size is 512
 Warning: BIOS sector numbering starts with sector 1
 Information from DOS bootblock is:
 The data for partition 1 is:
 sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
     start 63, size 16771797 (8189 Meg), flag 80 (active)
         beg: cyl 0/ head 1/ sector 1;
         end: cyl 1023/ head 254/ sector 63
 The data for partition 2 is:
 <UNUSED>
 The data for partition 3 is:
 <UNUSED>
 The data for partition 4 is:
 <UNUSED>
 
 
 > Andriy Gapon
 
 -- 
 Tim Newsham | www.thenewsh.com/~newsham | thenewsh.blogspot.com