Date: Thu, 1 Sep 2022 17:47:08 -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: <CAMtcK2qd%2BKstLC1oKZm9OPaOYh=gSHxYV=ZjCud2AF5G4n=-Aw@mail.gmail.com> In-Reply-To: <A99C0412-FD34-46D6-AB9A-AFC45FB10C10@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>
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--00000000000082510f05e7a712a7 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable yeah, I was pretty sure I was using the wrong tool=E2=80=A6thanks for this. So a further Q=E2=80=A6if I continue to use recoverdisk from ports to mirro= r 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 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 step, 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? Mirrored 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/ --00000000000082510f05e7a712a7 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <div dir=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 rec= overdisk from ports to mirror my boot disk to a copy, is it best practice t= o do this on the mirror after the mirroring is completed? For all I know th= ere 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 was set up. A backup you can't use isn't much use, as I hav= e learned (again, I expect). <br><br>On Thu, Sep 1, 2022 at 5:20 PM Dan Mah= oney <<a href=3D"mailto:freebsd@gushi.org">freebsd@gushi.org</a>> wro= te:<br>><br>> Fdisk is for old-school partitions (where disks had onl= y 1-4 primary partitions, and then subdivided those partitions into "s= lices" (bsdlabel).<br>><br>> I'm pretty sure the command you= 're looking for is:<br>><br>> gpart bootcode -b /boot/pmbr -p /bo= ot/gptboot -i 1 ada1<br>><br>> In english, this says:<br>><br>>= * Stick the "protective master boot record" on the root of the d= isk (/boot/pmbr)<br>> * Write a partition boot label from the file speci= fied...<br>> * to this indexed partition (-i 1)<br>> * ...on ada1<br>= ><br>> From there, you may need to tell the stage 0 loader where to f= ind your next bootable partition on the next boot() prompt.<br>><br>>= -Dan<br>><br>><br>> > On Sep 1, 2022, at 16:44, Dan Mahoney &l= t;<a href=3D"mailto:freebsd@gushi.org">freebsd@gushi.org</a>> wrote:<br>= > ><br>> ><br>> ><br>> >> On Sep 1, 2022, at 16:= 41, paul beard <<a href=3D"mailto:paulbeard@gmail.com">paulbeard@gmail.c= om</a>> wrote:<br>> >><br>> >> I have been mirroring t= he 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 ke= rnel, so I think I missed out on an additional step, writing an MBR or boot= sector, perhaps.<br>> >><br>> >> The files are all there= if I mount them from a VM with FreeBSD.I assume there is a way to make a m= ountable disk bootable. =C2=A0fdisk and gpart are available but it's be= en a long time since I messed around with those.<br>> ><br>> > = Let's start with the obvious: Can you post your disk layout?=C2=A0 Mirr= ored how?=C2=A0 Gmirror/ZFS/Hardware raid/etc?=C2=A0 MBR or Gpart?<br>> = ><br>> > What commands have you tried thusfar?<br>> ><br>>= ; > What does the boot so far look like (i.e. are you hitting the stage = 0 boot loader, and getting the loader prompt?)<br>> ><br>> > Mo= re info required, please, but this sounds very fixable.<br>> ><br>>= ; > -Dan<br>><br><br><br>--<br>Paul Beard / <a href=3D"http://www.pau= lbeard.org/">www.paulbeard.org/</a></div> --00000000000082510f05e7a712a7--
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