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Date:      Fri, 29 May 2015 18:22:17 -0700
From:      David Newman <>
Subject:   Re: Missing boot loader
Message-ID:  <>
In-Reply-To: <>
References:  <> <> <> <> <> <>

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On 5/29/15 12:22 PM, Warren Block wrote:
> On Fri, 29 May 2015, David Newman wrote:
>> On 5/29/15 8:46 AM, Warren Block wrote:
>>> On Fri, 29 May 2015, David Newman wrote:
>>>> On 4/6/15 9:28 PM, Olivier Nicole wrote:
>>>>> My solution is
>>>>> certainly not the best/fastest, but it works.
>>>> Thanks for this. After following the clone instructions, restore
>>>> appears
>>>> to work, but the system comes up with a "Missing boot loader" error.
>>>> This is perhaps because the next-to-last step from the live CD is:
>>>> cd /
>>>> mount -o rw /dev/da0p1 /mnt
>>>> gpart bootcode -b /mnt/boot/pmbr -p /mnt/boot/gptboot -i 1 da0
>>>> And that returns "/dev/da0p1: Operation not permitted" even though
>>>> da0p1
>>>> is the target system's root/boot partition.
>>> In this code, da0 is the source disk, where the bootcode files are read.
>>> It is mounted on /mnt.  So there are two reasons that gpart cannot write
>>> bootcode to da0p1.  First, it is mounted, and second, it is filesystem
>>> partition, not a freebsd-boot partition.
>>> The target disk cannot be da0p1.  Maybe it is a simple typo, and either
>>> the second or third line was meant to be ada0 rather than da0.
>> Thanks for your email. Backstory: This VM is a dump/restore clone of
>> another machine that has no separate boot partition. Here's /etc/fstab
>> from the source machine:
>> /dev/ada0p2    /        ufs    rw    1    1
>> /dev/ada0p3    none        swap    sw    0    0
> On a GPT disk, FreeBSD uses a freebsd-boot partition to hold the
> bootcode.  This is binary code written to that partition, which does not
> have a filesystem.  It does *not* contain /boot, which is instead part
> of /.
> Because the freebsd-boot partition is not needed after boot, it is not
> mentioned in /etc/fstab.  Look at the output of 'gpart show' instead.
>> And on the new target VM:
>> /dev/da0p1    /        ufs    rw    1    1
>> /dev/da0p2    none        swap    sw    0    0
> This disk is mountable, but because there is no freebsd-boot partition,
> it will not be bootable.  (Well, it might be possible to add a
> freebsd-boot partition after the existing partitions, but I'd avoid that
> because it is unusual and may come back to haunt you at the worst
> possible time.)
>> I don't understand the bit about 'ada0', since 'gpart list' shows only
>> da0 and two providers under it.
> The original disk was ada0, the new one is da0.  If the partitions had
> been created properly on da0 (with p1 being the freebsd-boot partition),
> it would be possible to mount da0p2 (/), read the bootcode from a file
> in the /boot directory there, and write it to da0p1.
>> The source machine has boot files in its root partition, under /boot.
> Those are copies of the binary bootcode that must be written to a
> freebsd-boot partition to make a disk bootable.
> Disk Setup On FreeBSD:

Bingo. Thanks, Warren!

I completely missed the necessity for a boot partition -- the fstab
table and 'gpart show' output of the source machine should have been a clue.

Remade the partitions, redid the restore, and now the target VM boots as
expected. Thanks again!


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