On 09/27/2016 11:54 AM, ron7000 wrote:
> everything i've read about the soft option says to never use it, and can
> easily lead to data corruption.
>> Do not try to access mountpoints that are not there; that's just silly.

> i think you are missing my point, otherwise you are effectively saying
> don't use nfs because there is no way to handle the situation when a
> system that is an nfs-server goes down.

I definitely do not mean to discourage NFS use that much. I also cannot
duplicate your issue, at least not entirely, though my system's setup
(SLES 12) is using NFSv4, which you indicated is not the case with your
systems One thing that is similar-ish, is that if I am on an NFS client
system, and I then stop the NFS service on my server (not stopping the
entire server yet, just its NFS service), and then I go into the parent
directory of my mountpoint (/import), I cannot do a long-listing of the
directory contents, which would effectively be the mount points. Where
you have your mount point, I think, right off the root of your filesystem
(/), perhaps that is something similar. If you have something in a login
script trying to do a listing of the filesystem root, or doing something
equivalent with another command, perhaps that is where it blocks because
of the inability to look at the mount point fully.

Even in that case, after I lock up the 'ls' command, hitting Ctrl+c fixes
it, so perhaps try that during your SSH login that hangs to see if you are
in a login script. If you are, figure out which one, and where, and maybe
a fix can be implemented that way too. It would be neat to see what
happens if you move your mountpoints one level deeper, for example,
instead of /scratch-hpc2 you put them at /import/scratch-hpc2 or somewhere
else not as public as the root of the filesystem.

If you cannot get in even with Ctrl+c after the SSH login takes the
username and password successfully, the next step is to figure out what is
blocking, and for that I would use strace. While already logged into the
box, find a command that locks things up, like loading a new shell
('bash') may. To use strace, run the following and be prepared for a lot
of output so be sure your history is big:

strace -ttt -ff bash
Post the output here and let's see what the last line is.

Good luck.

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