9.1 won't install - GEOM/GRAID issues

[Michael Powell]

Mike. wrote:
[snip]
> 
> Thanks for the reply.   The disk in question has never been used for
> RAID, so if there is RAID metadata on the disk, I do not know how it
> got there.  The disk is (I believe --- it's been a while since I have
> been inside that box) on a Promise SATA RAID controller, but RAID is
> not used and has never been used (I have a 3Ware controller for RAID on
> that box).
> 
> When things settle down, I'll try to figure out how to sanitize the
> disk and try to install 9.1 again.
> 

If somehow some RAID controller ever wrote out metadata to the disk it will 
be the last sector or two at the very end. Sometimes some GPT partitioning 
schemes corrupt this too. If some alien form of GPT partitioning or some 
form of RAID has written anything to this area it will throw an error when 
GEOM 'tastes' the disk. 

You can zero both these areas with dd if=/dev/zero plus disk plus some 
arithmetic. Another way, and I do sometimes when I go to reuse a disk that's 
been used for a while, is to use the mfr's diagnostic utility. I know the WD 
diag utility has an option to write 0's to the entire drive. Sometimes I do 
this and then run the extended diags just to get a 'feel good' factor on the 
media. Trouble with this is the larger the disk gets the longer it takes. I 
just like media scans on old disks before I recycle them to a new project.

-Mike