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Date:      Thu, 1 Sep 2022 19:10:10 -0700
From:      paul beard <paulbeard@gmail.com>
To:        Dan Mahoney <freebsd@gushi.org>
Cc:        FreeBSD-questions <freebsd-questions@freebsd.org>
Subject:   Re: making a disk/slice bootable
Message-ID:  <CAMtcK2rsnAJUTrLfmUJxKOwZJkOW1UXDs5U--8Kz=QHuM%2B-eog@mail.gmail.com>
In-Reply-To: <03F3F917-CCF5-44BB-85F0-00AD3ADF9818@gushi.org>
References:  <CAMtcK2r4L3SCba4EZt73=F2=fnBnEPGvEL3GCM_38R8_e5meXg@mail.gmail.com> <07BE254D-7701-47F2-94E3-09ED7229FB2B@gushi.org> <A99C0412-FD34-46D6-AB9A-AFC45FB10C10@gushi.org> <CAMtcK2qd%2BKstLC1oKZm9OPaOYh=gSHxYV=ZjCud2AF5G4n=-Aw@mail.gmail.com> <03F3F917-CCF5-44BB-85F0-00AD3ADF9818@gushi.org>

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Thanks! That worked just fine but the mirrored/cloned disk has issues. And
with no way to get 11.x source, I think I have some decisions to make about
this system: upgrade and somehow move all the services across or just quit
pretending I understand any of this stuff.

Thanks again for the help=E2=80=A6

On Thu, Sep 1, 2022 at 5:52 PM Dan Mahoney <freebsd@gushi.org> wrote:

> I haven't used recoverdisk.  If you're going to mirror, use one of the
> other things I mentioned.  gmirror is low-impact and easy enough to use a=
nd
> supported by the various boot loaders.
>
> If you're just cloning disk to similar disk with rsync, you should not
> need to do this more than once, unless maybe if you upgrade your system.
> Normal freebsd-update upgrades do not generally touch the boot blocks.  T=
he
> best advice I can give is "test this BEFORE you need it".  Rip your prima=
ry
> drive out and see if you still boot.
>
> For a lightweight system, even zfs mirroring is okay, but it does use som=
e
> ram for caching and the like, so I wouldn't try it with a tiny embedded b=
ox.
>
> -Dan
>
> On Sep 1, 2022, at 17:47, paul beard <paulbeard@gmail.com> wrote:
>
> yeah, I was pretty sure I was using the wrong tool=E2=80=A6thanks for thi=
s.
>
> So a further Q=E2=80=A6if I continue to use recoverdisk from ports to mir=
ror my
> boot disk to a copy, is it best practice to do this on the mirror after t=
he
> mirroring is completed? For all I know there is a far better way to do th=
at
> but this is a FreeBSD 11 system (!) that has just been doing its thing fo=
r
> some years. So it worked (more or less) when it was set up. A backup you
> can't use isn't much use, as I have learned (again, I expect).
>
> On Thu, Sep 1, 2022 at 5:20 PM Dan Mahoney <freebsd@gushi.org> wrote:
> >
> > Fdisk is for old-school partitions (where disks had only 1-4 primary
> partitions, and then subdivided those partitions into "slices" (bsdlabel)=
.
> >
> > I'm pretty sure the command you're looking for is:
> >
> > gpart bootcode -b /boot/pmbr -p /boot/gptboot -i 1 ada1
> >
> > In english, this says:
> >
> > * Stick the "protective master boot record" on the root of the disk
> (/boot/pmbr)
> > * Write a partition boot label from the file specified...
> > * to this indexed partition (-i 1)
> > * ...on ada1
> >
> > From there, you may need to tell the stage 0 loader where to find your
> next bootable partition on the next boot() prompt.
> >
> > -Dan
> >
> >
> > > On Sep 1, 2022, at 16:44, Dan Mahoney <freebsd@gushi.org> wrote:
> > >
> > >
> > >
> > >> On Sep 1, 2022, at 16:41, paul beard <paulbeard@gmail.com> wrote:
> > >>
> > >> I have been mirroring the virtual disk in a FreeBSD vm for a couple
> of years and the main disk got corrupted. The mirrored disk doesn't boot,
> says it can't find a kernel, so I think I missed out on an additional ste=
p,
> writing an MBR or boot sector, perhaps.
> > >>
> > >> The files are all there if I mount them from a VM with FreeBSD.I
> assume there is a way to make a mountable disk bootable.  fdisk and gpart
> are available but it's been a long time since I messed around with those.
> > >
> > > Let's start with the obvious: Can you post your disk layout?  Mirrore=
d
> how?  Gmirror/ZFS/Hardware raid/etc?  MBR or Gpart?
> > >
> > > What commands have you tried thusfar?
> > >
> > > What does the boot so far look like (i.e. are you hitting the stage 0
> boot loader, and getting the loader prompt?)
> > >
> > > More info required, please, but this sounds very fixable.
> > >
> > > -Dan
> >
>
>
> --
> Paul Beard / www.paulbeard.org/
>
>
>

--=20
Paul Beard / www.paulbeard.org/

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<div dir=3D"ltr">Thanks! That worked just fine but the mirrored/cloned disk=
 has issues. And with no way to get 11.x source, I think I have=C2=A0some d=
ecisions=C2=A0to=C2=A0make about this system: upgrade and somehow move all =
the services across or just quit pretending I understand=C2=A0any of this s=
tuff.=C2=A0<br><div><br></div><div>Thanks again for the help=E2=80=A6</div>=
</div><br><div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">=
On Thu, Sep 1, 2022 at 5:52 PM Dan Mahoney &lt;<a href=3D"mailto:freebsd@gu=
shi.org">freebsd@gushi.org</a>&gt; wrote:<br></div><blockquote class=3D"gma=
il_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left-width:1px;border-le=
ft-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div st=
yle=3D"word-wrap:break-word;line-break:after-white-space">I haven&#39;t use=
d recoverdisk.=C2=A0 If you&#39;re going to mirror, use one of the other th=
ings I mentioned. =C2=A0gmirror is low-impact and easy enough to use and su=
pported by the various boot loaders.<div><br></div><div>If you&#39;re just =
cloning disk to similar disk with rsync, you should not need to do this mor=
e than once, unless maybe if you upgrade your system.=C2=A0 Normal freebsd-=
update upgrades do not generally touch the boot blocks.=C2=A0 The best advi=
ce I can give is &quot;test this BEFORE you need it&quot;.=C2=A0 Rip your p=
rimary drive out and see if you still boot.<br><div><br></div><div>For a li=
ghtweight system, even zfs mirroring is okay, but it does use some ram for =
caching and the like, so I wouldn&#39;t try it with a tiny embedded box.<br=
><div><br></div><div>-Dan</div><div><br><blockquote type=3D"cite"><div>On S=
ep 1, 2022, at 17:47, paul beard &lt;<a href=3D"mailto:paulbeard@gmail.com"=
 target=3D"_blank">paulbeard@gmail.com</a>&gt; wrote:</div><br><div><div di=
r=3D"ltr">yeah, I was pretty sure I was using the wrong tool=E2=80=A6thanks=
 for this. <br><br>So a further Q=E2=80=A6if I continue to use recoverdisk =
from ports to mirror my boot disk to a copy, is it best practice to do this=
 on the mirror after the mirroring is completed? For all I know there is a =
far better way to do that but this is a FreeBSD 11 system (!) that has just=
 been doing its thing for some years. So it worked (more or less) when it w=
as set up. A backup you can&#39;t use isn&#39;t much use, as I have learned=
 (again, I expect). <br><br>On Thu, Sep 1, 2022 at 5:20 PM Dan Mahoney &lt;=
<a href=3D"mailto:freebsd@gushi.org" target=3D"_blank">freebsd@gushi.org</a=
>&gt; wrote:<br>&gt;<br>&gt; Fdisk is for old-school partitions (where disk=
s had only 1-4 primary partitions, and then subdivided those partitions int=
o &quot;slices&quot; (bsdlabel).<br>&gt;<br>&gt; I&#39;m pretty sure the co=
mmand you&#39;re looking for is:<br>&gt;<br>&gt; gpart bootcode -b /boot/pm=
br -p /boot/gptboot -i 1 ada1<br>&gt;<br>&gt; In english, this says:<br>&gt=
;<br>&gt; * Stick the &quot;protective master boot record&quot; on the root=
 of the disk (/boot/pmbr)<br>&gt; * Write a partition boot label from the f=
ile specified...<br>&gt; * to this indexed partition (-i 1)<br>&gt; * ...on=
 ada1<br>&gt;<br>&gt; From there, you may need to tell the stage 0 loader w=
here to find your next bootable partition on the next boot() prompt.<br>&gt=
;<br>&gt; -Dan<br>&gt;<br>&gt;<br>&gt; &gt; On Sep 1, 2022, at 16:44, Dan M=
ahoney &lt;<a href=3D"mailto:freebsd@gushi.org" target=3D"_blank">freebsd@g=
ushi.org</a>&gt; wrote:<br>&gt; &gt;<br>&gt; &gt;<br>&gt; &gt;<br>&gt; &gt;=
&gt; On Sep 1, 2022, at 16:41, paul beard &lt;<a href=3D"mailto:paulbeard@g=
mail.com" target=3D"_blank">paulbeard@gmail.com</a>&gt; wrote:<br>&gt; &gt;=
&gt;<br>&gt; &gt;&gt; I have been mirroring the virtual disk in a FreeBSD v=
m for a couple of years and the main disk got corrupted. The mirrored disk =
doesn&#39;t boot, says it can&#39;t find a kernel, so I think I missed out =
on an additional step, writing an MBR or boot sector, perhaps.<br>&gt; &gt;=
&gt;<br>&gt; &gt;&gt; The files are all there if I mount them from a VM wit=
h FreeBSD.I assume there is a way to make a mountable disk bootable. =C2=A0=
fdisk and gpart are available but it&#39;s been a long time since I messed =
around with those.<br>&gt; &gt;<br>&gt; &gt; Let&#39;s start with the obvio=
us: Can you post your disk layout?=C2=A0 Mirrored how?=C2=A0 Gmirror/ZFS/Ha=
rdware raid/etc?=C2=A0 MBR or Gpart?<br>&gt; &gt;<br>&gt; &gt; What command=
s have you tried thusfar?<br>&gt; &gt;<br>&gt; &gt; What does the boot so f=
ar look like (i.e. are you hitting the stage 0 boot loader, and getting the=
 loader prompt?)<br>&gt; &gt;<br>&gt; &gt; More info required, please, but =
this sounds very fixable.<br>&gt; &gt;<br>&gt; &gt; -Dan<br>&gt;<br><br><br=
>--<br>Paul Beard / <a href=3D"http://www.paulbeard.org/" target=3D"_blank"=
>www.paulbeard.org/</a></div>
</div></blockquote></div><br></div></div></div></blockquote></div><br clear=
=3D"all"><div><br></div>-- <br><div dir=3D"ltr" class=3D"gmail_signature">P=
aul Beard / <a href=3D"http://www.paulbeard.org/" target=3D"_blank">www.pau=
lbeard.org/</a><br></div>

--000000000000739d8a05e7a83bc2--



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