Problem adding 1TB SATA disk to system

Andy Wodfer wodfer at
Fri Sep 24 11:55:27 UTC 2010

On Thu, Sep 16, 2010 at 6:17 PM, Michael Powell <nightrecon at>wrote:

> Andy Wodfer wrote:
> > I'm running FreeBSD 8.0 release (will upgrade to 8.1 STABLE tonight).
> > However, I'm having big problems adding a new harddrive to the system. I
> > want a separate 1TB SATA installed to recover backup files on, but when I
> > add it I only get error messages:
> >
> > dmesg:
> >
> > ad2: 953869MB <WDC WD1000FYPS-01ZKB0 02.01B01> at ata1-master SATA300
> > GEOM: ad2: corrupt or invalid GPT detected.
> > GEOM: ad2: GPT rejected -- may not be recoverable.
> > GEOM: ufsid/4c80e66f50f43e15: corrupt or invalid GPT detected.
> > GEOM: ufsid/4c80e66f50f43e15: GPT rejected -- may not be recoverable.
> >
> > I've tried label and fdisk, but I can't get it to work.
> >
> [snip]
> I do not believe you can utilize fdisk and label for this. Since it appears
> there may be a possibility of a garbage MBR present this will wipe it:
> Boot a LiveFS CD, then at a root prompt do:
> sysctl kern.geom.debugflags=16  and:
> dd if=/dev/zero of=/dev/adx oseek=1 bs=512 count=1
> where x equals your drive number. This will zero out any old MBR.
> You will need to set this up with gpart instead of fdisk. More details in
> man gpart and possibly glabel. The devil is in the details, but this may be
> enough to get you pointed down the road.

I couldn't get it to work. My solution was to remove the 1TB drive and
install 2x500GB drives in a small RAID instead. Made life so much easier.


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