failed to create gmirror with the handbook instructions

Andy Zammy andyzammy at
Tue Oct 8 22:31:13 UTC 2013

# gpart show ada0s1
gpart: No such geom: ada0s1

By the way, this is after a restart of the machine.

There's nothing to back up, I'm installing a fresh os, so I just install on
one drive, plug the other in, and start following the handbook instructions
for this method. So the only thing in loader.conf is geom_mirror_load="YES".

I'll rephrase the question: given that the handbook originally wanted me to
dump from ada0s1 to the mounted mirror/gm0s1 (which was ada1 at the time),
and I cannot do this, would it be enough to dump from mirror/gm0s1 (which
is what ada0 is now mounted as), to ada1s1 (even though this *should* be
the other way around, it's equivalent as far as i can see, isn't it?)?

On 8 October 2013 22:59, Warren Block <wblock at> wrote:

> On Tue, 8 Oct 2013, Andy Zammy wrote:
>  This is actually trickier than it first looked. First I got into single
>> user mode by supplying 'shutdown now', but the tunefs commands all failed
>> with the following:
>> #tunefs -j disable /dev/ada0s1a
>> Clearing journal flags from inode 4
>> tunefs: Failed to write journal inode: Operation not permitted
>> tunefs: soft updates journalling cleared but soft updates still set.
>> tunefs: remove .sujournal to reclaim space
>> tunefs: /dev/ada0s1a: failed to write superblock
>> I tried the dump command on the off-chance, and it failed with the
>> original errors. Is there anything you can recommend?
>> I then noticed you specified to boot into single user more, so I
>> restarted the machine, with only ada0 attached. Because the handbook wants
>> me to use the mirror/gm0sX devices, I swapped
>> my fstab file back to the original. The boot loader now only seems to
>> recognise the mirror/gm0 nodes, the original ada0sX are gone (though ada0
>> still shows up).
> I don't know what would do that.  The device nodes on the original drive
> should be untouched until it is added back to the mirror.  What does
>   gpart show ada0s1
> show?  Did you make a backup of the original drive first?  Is there an
> entry for vfs.root.mountfrom in /boot/loader.conf?
>  I'm not sure if it's acceptable to do the dump by booting the 1st hard
>> drive using the mirror/gm0, and then dump to the 2nd hard drive by mounting
>> what will be ada1sX. Is this okay to do?
> Sorry, I don't quite understand the question.  The mirror will not be
> usable until a good copy of the original drive is made to it.

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