Can't *write* to a hard disk, not even a slice using fdisk(8).

Joan Picanyol i Puig lists-gmane at
Sat Apr 10 18:44:56 PDT 2004

On Sun, 11 Apr 2004 00:45:14 +0200, Julien Gabel wrote:
>> GEOM doesn't let you touch the disk if some partition is mounted off it.
>> Try setting kern.geom.debugflags to 1

I suck. This should have said:

GEOM doesn't let you write to an active device, except if you set

> I changed the sysctl's flag :
>  # sysctl kern.geom.debugflags=1
>  kern.geom.debugflags: 0 -> 1

so this should be 16 not 1

>  # mount
>  /dev/ar0s1a on / (ufs, local)
>  devfs on /dev (devfs, local)
>  /dev/ad8s1d on /home (ufs, local, nodev, noexec, nosuid, with quotas,
> soft-updates)
>  /dev/ar0s1e on /tmp (ufs, local, nodev, nosuid, soft-updates)
>  /dev/ar0s1f on /usr (ufs, local, soft-updates)
>  /dev/ar0s1d on /var (ufs, local, noexec, soft-updates)

If ad8 is part of ar0 GEOM will try to keep you from shooting yourself on
the foot. You should take ad8 out of the array first.

> Because the problematic disk is not actually used, I can try some commands
> on it if someone think it may be interesting.

On the hardware side, you should look for some diagnostic tool from the


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