ls -l /path/to/zfs hangs; ls -a is fine

[Chris Stankevitz]

EDIT: the problem went away -- it is working now.  But of course I'd 
love to hear your WAG or your idea about how to probe further if it 
happens again.  I get the feeling that zfs was "busy doing something" 
and when it finished it was able to offer me a "ls -l".

=====

Hi,

1. "ls -l" hangs for a particular ZFS filesystem.

2. CTRL-C brings me back to shell.

3. "ls -a" is okay

4. Other ZFS filesystems in the same pool are okay.

5. "zpool status" shows no trouble.

6. When I first noticed the problem, I was able to cd to a parent 
directory and then "ls -l child/".  However, after a minute or so even 
that started to hang all the way down to the root of the FS.

7. I use samba/winbind/nsswich to give files owners that are not in 
/etc/passwd; however, I do not believe that is the direct source of the 
trouble because of (6) above: I was able to see these file owners for a 
little while.

8. I use net/unison-nox11 to sync this particular filesystem with 
another system.  Unison is an application that copies files, modes, and 
owners between systems.

The system is at a remote location so I hesitate to try to unmount and 
remount the filesystem -- or export and import the pool -- for fear that 
the entire system will hang requiring someone to pull the plug.  (had to 
pull the plug once when I was using nullfs to remount a ZFS directory 
elsewhere -- apparently this is not supported and causes deadlocks).

Please let me know if you have any tips that will allow me to determine 
what is wrong.


Thank you,

Chris