boot0cfg on does not set default selection on gmirror device

[Arrigo Marchiori]

Hello all,

On Fri, Oct 21, 2016 at 08:41:33AM -0600, Warner Losh wrote:

> On Fri, Oct 21, 2016 at 5:39 AM, Patrick M. Hausen <hausen at punkt.de> wrote:
> > Hi, all,
> >
> > we are repeatedly bitten by the following misbehaviour of boot0cfg:
> >
> > root at hd45:/usr/local # boot0cfg -s 1 mirror/m0
> > root at hd45:/usr/local # boot0cfg -v mirror/m0
> > #   flag     start chs   type       end chs       offset         size
> > 1   0x80      1:  0: 1   0xa5   1022:254:63        16065     16418430
> > 2   0x00   1023:  0: 1   0xa5   1020:254:63     16434495     16418430
> > 3   0x00   1021:  0: 1   0xa5    768:254:63     32852925   1920667140
> >
> > version=1.0  drive=0x80  mask=0xf  ticks=182  bell=  (0x7)
> > options=packet,update,nosetdrv
> > default_selection=F2 (Slice 2)
> >
> > So, while it should have set the default to slice 1, it simply didn't.
> >
> > gpart on the other hand works as expected:
> >
> > root at hd45:/usr/local # gpart set -a active -i 1 mirror/m0
> > active set on mirror/m0s1
> > root at hd45:/usr/local # gpart show mirror/m0
> > =>        63  1953525104  mirror/m0  MBR  (932G)
> >           63       16002             - free -  (7.8M)
> >        16065    16418430          1  freebsd  [active]  (7.8G)
> >     16434495    16418430          2  freebsd  (7.8G)
> >     32852925  1920667140          3  freebsd  (916G)
> >   1953520065        5102             - free -  (2.5M)
> >
> > But the "active" flag alone is not enough to convince boot0 to actually boot that partition.
> >
> > Additional info:
> >
> > root at hd45:/usr/local # uname -a
> > FreeBSD hd45.hosting.punkt.de 10.3-RELEASE-p10 FreeBSD 10.3-RELEASE-p10 #0 r306942: Mon Oct 10 10:29:14 UTC 2016     root@:/usr/obj/nanobsd.hosting/usr/src/sys/GENERIC  amd64
> > root at hd45:/usr/local # gmirror status
> >      Name    Status  Components
> > mirror/m0  COMPLETE  ada0 (ACTIVE)
> >                      ada1 (ACTIVE)
> >
> >
> > The only way to actually switch the boot0 default selection is:
> >
> > root at hd45:/usr/local # sysctl kern.geom.debugflags=16
> > kern.geom.debugflags: 0 -> 16
> > root at hd45:/usr/local # boot0cfg -s 1 ada0
> > root at hd45:/usr/local # boot0cfg -s 1 ada1
> > root at hd45:/usr/local # boot0cfg -v mirror/m0
> > #   flag     start chs   type       end chs       offset         size
> > 1   0x80      1:  0: 1   0xa5   1022:254:63        16065     16418430
> > 2   0x00   1023:  0: 1   0xa5   1020:254:63     16434495     16418430
> > 3   0x00   1021:  0: 1   0xa5    768:254:63     32852925   1920667140
> >
> > version=1.0  drive=0x80  mask=0xf  ticks=182  bell=  (0x7)
> > options=packet,update,nosetdrv
> > default_selection=F1 (Slice 1)
> >
> >
> > Any hints what's going on, here? Obviously it is possible to manipulate
> > the MBR of a gmirror device - as gpart proves. The boot0cfg pops up
> > since FreeBSD 8 when we started using a mirrored NanoBSD setup.
> 
> Any chance you can migrate to using gpart? Is boot0cfg still
> referenced in NanoBSD somewhere?

Ahem... For what it's worth... I cannot help not pointing this old PR
out: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=186030

Best regards,
-- 
rigo

http://rigo.altervista.org