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Simulators >> Circuit Simulators >> SPECTRE : remote simulations
https://designers-guide.org/forum/YaBB.pl?num=1200581122

Message started by olifant on Jan 17^th, 2008, 6:45am

Title: SPECTRE : remote simulations
Post by olifant on Jan 17^th, 2008, 6:45am

Since I need to run a number of extensive SPECTRE analyses, I'm using the different servers available at out research group to do these simulations using a remote shell (SSH in Linux). However, the simulations stop after 10 ks (approx. 2 hours and 46 minutes ). The error message I get is "CPU time limit exceeded". In addition, the "ulimit" parameter in Linux is set at "unlimited", which in my opinion indicates that the problem originates from SPECTRE. Also, and this is quite strange, there seem to be no time limit restrictions when I perform SPECTRE simulations on my computer: these keep on going for hours. Is this an extra option I have to set in SPECTRE ? I've not found any document on the internet or any indication in the SPECTRE manuals mentioning this effect. Does anybody know how I can overcome this limitation ?

Thanks for the help !

Title: Re: SPECTRE : remote simulations
Post by Ken Kundert on Jan 17^th, 2008, 4:53pm

Perhaps it is because the ssh shell is dying. Did you run Spectre in the background so that it will continue to run even if the shell that started it is killed?

Often ssh connections will automatically terminate if there is no use for a long period of time, however you can configure ssh to periodically sent keep-alives to prevent this from happening.

-Ken

Title: Re: SPECTRE : remote simulations
Post by olifant on Jan 18^th, 2008, 2:27am

Indeed, you are right: it is probably the ssh shell which is terminating after a long period of (apparent) inactivity.

After reading your comment, I launched the SPECTRE script in background (I used the LINUX command "nohup runspectre &" ), and now it works fine.

Thanks for the help !