Re: nfs unmount: can it be done from (to) a croaked system?

[christos%astron.com@localhost (Christos Zoulas)]

In article <201705221949.56425.mlr%rse.com@localhost>,
Mike Riechers  <mlr%rse.com@localhost> wrote:
>Hello, all.
>
>A few weeks ago one of our computers bit the big one: the root disc
>drive croaked (bad).  One of these days I'll get to replacing the
>drive, but I'm not shedding too many tears, for 1)it's a little used
>system, and 2) the important data was on other drives.
>
>What is annoying is, however, the fact that we had files nfs mounted
>on our network that were serviced from this computer.  Now any time we
>do a "df", an unmount, or any operation that references the nfs from
>that computer, the program "locks up," and ps shows:
>
>             D       Marks a process in device or other short term,
>                     uninterruptible wait.
>
>I did a "df" on one of our computers a couple of weeks ago, and ps
>still shows the process in device or other short term, uninterruptible
>wait.  So much for short term.
>
>I believe that the df inquiry is going to wait forever, demanding to
>palaver with the nfs that isn't there anymore.  (It's inconvenient to
>try to remember to do a "df -l," and of course, there goes info
>concerning my other nfs mounts.)
>
>I tried a "umount -fh mydeadcomputer.com" on the nfs mount, but all
>that got me was a locked-up "umount."
>
>I've rebooted one computer, and of course that worked, but I'd rather
>not do the same thing to all the rest.  Is there a more elegant
>solution I'm missing?
>
>I've tried starting up another computer to imitate the failed one as
>to IP and interface name, but that didn't work.  It looks like the
>only thing that will satisfy my live computers is an actual commune
>with the dead nfs system (or a reboot).
>
>Any help?  Thanks in advance,

Umount -f is supposed to work, but it never has. Please file a PR.

christos