Date: Mon, 02 Jul 2007 19:24:13 +0000 From: Harry Newton <hn+freebsd@yewbarrow.net> To: freebsd-geom@freebsd.org Cc: Arne =?iso-8859-1?q?W=F6rner?= <arne_woerner@yahoo.com> Subject: Re: gmirror on a slice uncertainty Message-ID: <87ved2zk0y.fsf@vm.yewbarrow.net> References: <963281.43796.qm@web30315.mail.mud.yahoo.com>
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Arne "W=F6rner" <arne_woerner@yahoo.com> writes:
[...]
>> > 41929650 =3D=3D 41929587+63
>> > This is the beginning of slice 2 (see fdisk)...
>> > I would guess, that slice 2 ends on the last sector of the disk, so th=
at
>> > gmirror is disturbed (it doesnt know if ad4 or ad4s2 (which share both=
the
>> > same last sector) is its underlying disk)...
>>=20
>> I haven't followed this. If I look at the disk with sysinstall:
>>=20
>> Disk name: ad4 FDISK Partiti=
on
>> Editor
>> DISK Geometry: 38913 cyls/255 heads/63 sectors =3D 625137345 sectors
>> (305242MB)
>>=20=20=20=20=20
>> Offset Size(ST) End Name PType Desc Subty=
pe=20
>> Flags
>>=20=20=20=20=20
>> 0 63 62 - 12 unused 0
>> 63 41929587 41929649 ad4s1 8 freebsd 165
>> 41929650 583207695 625137344 ad4s2 8 freebsd 165=
=20=20=20=20=20
>>=20=20=20=20=20
>> 625137345 5103 625142447 - 12 unused 0
>>
> Ohoh... OK - so ad4 and ad4s2 do not share the last sector...
> That makes my theory worthless...
>
>> I see there's space at the end of the disk. The code that produces the
>> message is in geom_bsd.c and is:
>>=20
>> if (rawoffset !=3D 0 && (off_t)rawoffset !=3D ms->mbroffset)
>> printf("WARNING: Expected rawoffset %jd, found %jd\n",
>> (intmax_t)ms->mbroffset/dl.d_secsize,
>> (intmax_t)rawoffset/dl.d_secsize);
>>
> Hmm... Dont know what that might mean...
I've reinstalled FreeBSD, but with the same slice values as given
above. I'm following Arne's suggestion and putting no disklabel on the
slice (the idea of having one lay in an abandoned partitioning scheme).
What I did exactly was:
gmirror label -v home ad4s2 ad6s2
Metadata value stored on ad4s2
Metadata value stored on ad6s2
gmirror load
... and then the machine froze. Looking in the logs, I see:
Jul 2 19:23:48 hydra kernel: GEOM_MIRROR: Device home created (id=3D25=
10448576).
Jul 2 19:23:48 hydra kernel: GEOM_MIRROR: Device home: provider ad6s2 =
detected.
Jul 2 19:23:48 hydra kernel: GEOM_MIRROR: Device home: provider ad4s2 =
detected.
Jul 2 19:23:48 hydra kernel: GEOM_MIRROR: Device home: provider ad6s2 =
activated.
Jul 2 19:23:48 hydra kernel: GEOM_MIRROR: Device home: provider ad4s2 =
activated.
Jul 2 19:23:48 hydra kernel: GEOM_MIRROR: Device home: provider mirror=
/home launched.
Jul 2 19:23:48 hydra kernel: WARNING: Expected rawoffset 0, found 4192=
9650
Jul 2 19:23:48 hydra last message repeated 13 times
Jul 2 19:23:48 hydra kernel: GEOM_MIRROR: Cannot add disk mirror/homec=
ccccccccccccc to home (error=3D17).
Jul 2 19:23:48 hydra kernel: WARNING: Expected rawoffset 0, found 4192=
9650
Jul 2 19:23:48 hydra last message repeated 38 times
Jul 2 19:23:48 hydra kernel: WARNING: Device name truncated! (mirror/h=
omecccccccccccccccccccccccccccccccccccccccccccccccccccc)
Jul 2 19:23:48 hydra kernel: WARNING: Expected rawoffset 0, found 4192=
9650
=20=20=20=20
with the last message repeated over 30 times before the reboot.
I repeated this after rebooting and got exactly the same. I then tried:
dd if=3D/dev/zero of=3D/dev/ad4s2 bs=3D512 count=3D79
dd if=3D/dev/zero of=3D/dev/ad6s2 bs=3D512 count=3D79
gmirror label -v home ad4s2 ad6s2
Metadata value stored on ad4s2
Metadata value stored on ad6s2
gmirror load
GEOM_MIRROR: Device home created (id=3D1852978599).
GEOM_MIRROR: Device home: provider ad6s2 detected.
GEOM_MIRROR: Device home: provider ad4s2 detected.
GEOM_MIRROR: Device home: provider ad6s2 activated.
GEOM_MIRROR: Device home: provider ad4s2 activated.
GEOM_MIRROR: Device home: provider mirror/home launched.
=20=20=20=20
So I am now quite concerned, and cautious about putting any data onto this =
machine. Does anyone have any ideas about this, and would you suggest this =
is a software bug or faulty hardware ?
Thanks
- Harry
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