Manuel Bouyer wrote:

>Well, it looks like something is seriously broken on this system. Are you sure
>this drive is OK ? /usr shouldn't corrupt this way.
>
>  
>
Thank you for replying.
As far as I use it for FreeBSD,the drive is OK.

After I struggled for a while,I resolve the problem.
I incorrectly tried to use FreeBSD 's /usr partition for NetBSD's /usr
partition.
I reinstall NetBSD not to mount FreeBSD partitions.
I am happy NetBSD didn't break FreeBSD partitions.

Morio Miki.