Problem adding 1TB SATA disk to system

Michael Powell nightrecon at
Thu Sep 16 16:15:15 UTC 2010

Andy Wodfer wrote:

> Hi all,
> 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.

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. 


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