[Simh] SIMH-VMS on Linux (CentOS) Host running slow at times

[Kevin Handy]

Michael Copini wrote:
> In the past (two years ago) I was able to compile and run SIMH for vax
> on a CentOS 4.5 system. In fact the system has run very nicely for the
> last 18 month's in believe it or not a production environment in order
> to extend the live of an inventory application that used to run on a
> microvax 3100.
>
> Recently the VMS 7.3 on the SIMH 3.4 is running very slow. I have looked
> at various things that might be the cause of this but can not find
> anything. The only thing that I notice is that when the system is
> reported as being slow, the system time is  of by sometimes several
> hours. (Like yesterday the VMS time was 14:30 while the LINUX time was
> 17:33. By shutting down the VMS and the SIMH and restarting it the
> system get's it normal speed back.  But every so often in the last two
> month's it is showing this slowness.
>
> Anybody with Idea's where to look for a solution. System has run  
> unchanged for over a year without any problems.
>   
What else is running on that system? 'top' could be helpful here.

Could someone, wanting to use another application, be speeding up
his run time by 'nice'ing the emulator? They'll never admit to it, but
I've seen such in the past.