Frequently Asked Questions

Q1: My code runs on a single processor. How can I run multiple copies, each with different input parameters, with a single batch submission? Also, since the hosts each have multiple processors, if I allocate the whole system to one process, one CPU is just sitting idle. So how do I run two processes on each host?


A1: Ernie Valeo has created a script that allows you do do this.

Q2: Do you have pbs reporting tools/packages that provides more info than simple pbs-report?

A2: You don't have any other pbs reporting tools/packages that provide more info.

Q3: What is Muda?

A3: Muda is the Japanese term for waste and comes from Lean Enterprise/Manufacturing. In this context we refer to 'waiting/idle muda'. It's a ratio of how much of a jobs'time is spent suspended, as a ratio of suspend time to CPU time. Our goal is to drive muda to zero.

Q4: UserA runs 8-16 node jobs all the time, and he got 0.128 Efcy.  UserB runs single process jobs all the time, and he got 2.624 Efcy.  Can you explain this?  

A4: The explanation about the differences for Efcy of userA and userB is that MPI jobs spawn processes that are not being tracked by PBS. Therefore that would explain the difference.

Q5: Where is ghostview on portal?

A5: Please try ggv, which stands for Gnome Ghostview.

Q6: What is the maximum value that I can set for P4_GLOBMEMSIZE?

A6: Currently, on all PPPL cluster nodes, the maximum value for P4_GLOBMEMSIZE is 1073741824.

Q7: When I run mathematica on the portal systems, the fonts do not appear correctly.

A7: In your login file, you need to specify a font server from which to get the fonts. Add this line to your login file (.cshrc or .login or .bashrc): 
 xset +fp tcp/lynx.pppl.gov:7100