Bug 160801 - [zfs] zfsboot on 8.2-RELEASE fails to boot from root-on-zfs in MBR slice [regression]
Summary: [zfs] zfsboot on 8.2-RELEASE fails to boot from root-on-zfs in MBR slice [reg...
Status: Closed FIXED
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: 8.2-RELEASE
Hardware: Any Any
: Normal Affects Only Me
Assignee: freebsd-bugs (Nobody)
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2011-09-18 14:10 UTC by Camillo Särs
Modified: 2019-03-01 16:26 UTC (History)
1 user (show)

See Also:


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Description Camillo Särs 2011-09-18 14:10:07 UTC
/boot/zfsboot when installed fails to boot from root-on-zfs in MBR slice,
set up according to this:

<http://wiki.freebsd.org/RootOnZFS/ZFSBootPartition>

I upgraded from 8.1 to 8.2-RELEASE, and consequently upgraded my zfs
root pool to version 15.  Upgraded the bootloader in Fixit prompt to
allow booting from v15 pool.  After this, the system fails to boot,
and freezes after the "Boot:  F1" prompt with "-" on the screen.  See
this thread for example screenshot:

<http://forums.freebsd.org/showthread.php?t=22105>

MBR is used because of BIOS incompatibility with GPT as installed by
FreeBSD.

Fix: 

Install zfsboot from 9.0-BETA2, where the problem is fixed.
How-To-Repeat: Set up root-on-ZFS in MBR slice on 8.2-RELEASE according to:

<http://wiki.freebsd.org/RootOnZFS/ZFSBootPartition>

Reboot - system halts on "-".
Comment 1 Mark Linimon freebsd_committer freebsd_triage 2011-09-18 15:33:27 UTC
Responsible Changed
From-To: freebsd-amd64->freebsd-fs

Over to maintainer(s).
Comment 2 John Baldwin freebsd_committer freebsd_triage 2011-09-19 13:02:59 UTC
On Sunday, September 18, 2011 9:01:11 am Camillo SXrs wrote:
>=20
> >Number:         160801
> >Category:       amd64
> >Synopsis:       zfsboot on 8.2-RELEASE fails to boot from root-on-zfs in=
=20
MBR slice
> >Confidential:   no
> >Severity:       serious
> >Priority:       low
> >Responsible:    freebsd-amd64
> >State:          open
> >Quarter:       =20
> >Keywords:      =20
> >Date-Required:
> >Class:          sw-bug
> >Submitter-Id:   current-users
> >Arrival-Date:   Sun Sep 18 13:10:07 UTC 2011
> >Closed-Date:
> >Last-Modified:
> >Originator:     Camillo S=E4rs
> >Release:        8.2-RELEASE
> >Organization:
> >Environment:
> FreeBSD free 8.2-RELEASE FreeBSD 8.2-RELEASE #0: Thu Feb 17 02:41:51 UTC=
=20
2011     root@mason.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  amd64
>=20
> >Description:
> /boot/zfsboot when installed fails to boot from root-on-zfs in MBR slice,=
=20
set up according to this:
>=20
> <http://wiki.freebsd.org/RootOnZFS/ZFSBootPartition>
>=20
> I upgraded from 8.1 to 8.2-RELEASE, and consequently upgraded my zfs root=
=20
pool to version 15.  Upgraded the bootloader in Fixit prompt to allow booti=
ng=20
from v15 pool.  After this, the system fails to boot, and freezes after the=
=20
"Boot:  F1" prompt with "-" on the screen.  See this thread for example=20
screenshot:
>=20
> <http://forums.freebsd.org/showthread.php?t=3D22105>
>=20
> MBR is used because of BIOS incompatibility with GPT as installed by=20
=46reeBSD.
> >How-To-Repeat:
> Set up root-on-ZFS in MBR slice on 8.2-RELEASE according to:
>=20
> <http://wiki.freebsd.org/RootOnZFS/ZFSBootPartition>
>=20
> Reboot - system halts on "-".
> >Fix:
> Install zfsboot from 9.0-BETA2, where the problem is fixed.

Can you test 8.2-stable?  The various fixes made to zfsboot in 9 were merge=
d=20
to 8 after 8.2-release.

=2D-=20
John Baldwin
Comment 3 Camillo Särs 2011-09-19 15:07:26 UTC
Hi,

On 2011-09-19 15:02, John Baldwin wrote:
>> Install zfsboot from 9.0-BETA2, where the problem is fixed.
> 
> Can you test 8.2-stable?  The various fixes made to zfsboot in 9 were merged 
> to 8 after 8.2-release.

Unfortunately fixing this issue by installing zfsboot from 9.0-BETA2 was
a surprising amount of work, because of an incompatibility between the
9.0 USB installer GPT and the BIOS on this system.  It took quite a
while to recognize the root cause for that one.  I simply cannot boot
the system in question with the GPT pmbr used on the memstick of 9.0.
The BIOS locks completely.

I am very reluctant to risk breaking my currently running system, the
previous boot failure caused almost two weeks of downtime.

Does the 8.2-stable memstick image still use MBR?  If so, I could
conceivably try to copy the 9.0 zfsboot version to the 8.2-stable
memstick and test both.

Regards,
Camillo
Comment 4 Eitan Adler freebsd_committer freebsd_triage 2017-12-31 07:59:56 UTC
For bugs matching the following criteria:

Status: In Progress Changed: (is less than) 2014-06-01

Reset to default assignee and clear in-progress tags.

Mail being skipped
Comment 5 Eugene Grosbein freebsd_committer freebsd_triage 2019-03-01 16:26:16 UTC
zfsboot(8) manual page was fixed to provide correct instructions for usage with MBR. See PR 226714 for details.