how to unstick NFS freebsd 4.11

[Erik Stian Tefre]

On Thu, 2005-10-06 at 10:33 -0400, Vivek Khera wrote:
> Running a box I just upgraded on September 30 to 4.11-STABLE.
> 
> I have what appears a wedged NFS client.  The NFS server was recently  
> replaced with a new box after a failure.  However, now the client  
> can't umount the old one.  How can I clear this up without a reboot  
> (which is a *painful* thing to do on a production box):
> 
> [root at w02]# ls /n/lorax1
> ls: /n/lorax1: Stale NFS file handle
> [root at w02]# df
> Filesystem    1K-blocks     Used   Avail Capacity  Mounted on
> /dev/amrd0s2a    128990    41902   76770    35%    /
> /dev/amrd0s2f    201518    38654  146744    21%    /u/w02
> /dev/amrd0s2e    604718   396194  160148    71%    /usr
> /dev/amrd0s2g  15285872 12972172 1090832    92%    /var
> mfs:23            32206      354   29276     1%    /tmp
> procfs                4        4       0   100%    /proc
> [root at w02]# umount /n/lorax1
> umount: unmount of /n/lorax1 failed: Device busy
> [root at w02]# mount /n/lorax1
> mount: /n/lorax1: Stale NFS file handle
> 
> also, fstat shows nothing sitting inside of /n/lorax1 as its working  
> directory.

umount -f will probably work.

>From the umount manual:
-f      The filesystem is forcibly unmounted.  Active special devices
        continue to work, but all other files return errors if further
        accesses are attempted.  The root filesystem cannot be forcibly
        unmounted.

--
Erik Stian Tefre