gmirror failed with error 19.

Kevin Oberman kob6558 at
Thu Nov 3 22:26:54 UTC 2011

On Thu, Nov 3, 2011 at 4:50 AM, Sascha Klauder <sascha at> wrote:
> On Tue, 2011-11-01 11:23 +0400, Andrey V. Elsukov wrote:
>> On 28.10.2011 13:48, Sascha Klauder wrote:
>> >  GEOM_MIRROR: Device mirror/gm0 launched (2/2).
>> >  GEOM_PART: partition 1 has end offset beyond last LBA: 490350671 > 490350670
>> >  GEOM_PART: integrity check failed (mirror/gm0, MBR)
>> This is the main problem. Your MBR' slice is bigger than actual space
>> you have. The only way to fix this - recreate slice.
>  I've partioned and labeled the disk with sysinstall(8) from
> 8.2-RELEASE media.  Does 9.0 use different disk geometry cal-
> culation than 8.2 or is usage of gmirror the culprit?  Both
> 8.2 and 9.0 kernels report the disk having 490350672 sectors.
>> You can break your mirror, recreate the slice (NOTE: you must preserve
>> one sector for the gmirror's meta-data), then copy your data to the
>> newly created slice, then reboot from the new slice and recreate mirror.
>  I think I'd rather reinstall 9.0 from scratch, getting rid
> of MBR/disklabel as well.

While using gpart and the 9.0 installer has some real benefits, it
also has a few problems.

I ave a disk that I partitioned with bsdinstall from the 9.0
distribution media and it worked fine for a STAT disk, but I am unable
to boot te same disk when connected to a USB adapter. It shows up in
the boot list, but when I select it, the screen blanks for a few
seconds (<5) and the list re-appears. No errors, but my T520 BIOS
clearly is not happy with it. I have no idea how common htis issue
might be, but the T520 does have a UEFI BIOS.

As noted, GEOM wants the final sector on the disk for its metadata,
but GPT mandates that hte ast sector of the disk be used for a backup
of the boot sector. The leads to the potential ofr all kinds if
ugliness to develop, especially when BIOS, which knows nothing about
GEOM, is accessing the disk.
R. Kevin Oberman, Network Engineer
E-mail: kob6558 at

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