freebsd stable - Dec 2012 - 9.1 system hung with top open on console, yet responsive on ssh sessions?

I ran into a weird one, have a 9.1 test system (virtual in VMWare 
Workstation 9) that I left running logged into the console with top 
running.  The console the top process it was running appear to have 
hung, can't use ALT + F1,F2... to switch virtual consoles.  However I 
can log in to the system via ssh, if you run top you get the same 
information on the console, can even interact with it, switching search 
order and the like.  systat also seems to not display current 
information.  I can do everything I have tried through the console 
except I noticed that syslog isn't writing data and a /etc/rc.d/syslog 
restart hung as well.

This is just a test system running one single Java program (Ubiquiti 
UniFi controller software) that is responding just fine as well.  
Thought maybe it was disk access related, however I have confirmed that 
I can read and write to the disk, used dd if=/dev/random 
of=/.../random.out..., to each file system and was able to write to all 
of them.  Before I reboot the system (I have a feeling it won't reboot 
cleanly), I was curious if anyone else has ever seen this and what I 
should check to possibly identify what caused the problem.



-- 
Thanks,
    Dean E. Weimer
    http://www.dweimer.net/

On 2012-12-12 15:58, dweimer wrote:
> I ran into a weird one, have a 9.1 test system (virtual in VMWare
> Workstation 9) that I left running logged into the console with top
> running.  The console the top process it was running appear to have
> hung, can't use ALT + F1,F2... to switch virtual consoles.  However I
> can log in to the system via ssh, if you run top you get the same
> information on the console, can even interact with it, switching
> search order and the like.  systat also seems to not display current
> information.  I can do everything I have tried through the console
> except I noticed that syslog isn't writing data and a 
> /etc/rc.d/syslog
> restart hung as well.
>
> This is just a test system running one single Java program (Ubiquiti
> UniFi controller software) that is responding just fine as well.
> Thought maybe it was disk access related, however I have confirmed
> that I can read and write to the disk, used dd if=/dev/random
> of=/.../random.out..., to each file system and was able to write to
> all of them.  Before I reboot the system (I have a feeling it won't
> reboot cleanly), I was curious if anyone else has ever seen this and
> what I should check to possibly identify what caused the problem.
Might have discovered its probable related to 
<http://docs.freebsd.org/cgi/getmsg.cgi?fetch=294987+0+archive/2012/freebsd-stable/20120805.freebsd-stable>
as I noticed as well that that date command was always returning 
yesterdays date with the time set the same as top returned.

I went ahead and reset the virtual machine with the sysctl value set as 
listed in the thread linked to above.  will see if I hit the issue again 
or not.  Though this application will be moved off this test system to 
my actual serve as soon as the 9.1-Release is official.  so it may not 
be running long enough to know if that is the real solution.



-- 
Thanks,
    Dean E. Weimer
    http://www.dweimer.net/