Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

Your idev command line will contain 3 5 flags:   -m, -r, -A, -n, -N. Using the `idev -h` command, can you figure out what these 3 flags mean and what you told the system you wanted to do?

Expand
titleClick here to see if you are correct...

From the OPTIONS: section of the idev help output:

-m     minutes            sets time in minutes (default: 30)

-r     reservation_name   requests use of a specific reservation

-A     account_name       sets account name (default: -A none)

  -n     total_tasks        Total number of tasks

  -N     nodes              Number of nodes

So you will request an idev node using the reservation named Genome-Day, where Day is the day of the class I (Mon, Tue, Wed, Thur, Fri) and asked that it be charged to the account named UT-2015-05-18.

...

Code Block
languagebash
titleStarting an idev session
idev -r Genome-Tue -A UT-2015-05-18 -m ??? -n 48 -N 1

The very first line of output should be. 

...

Info
titleYou may be prompted asking how many tasks per node you would like if this is the first idev session you are launching.

The two most common choices would be 68 48 and 1 for 68 48 and 1 max possible independent commands at the same time. As long as you are letting the individual programs allocate the number of threads (ie --threads for some programs, -p or -j for others), this choice will not matter. If you want to run multiple commands at the same time (say with a commands file which puts each individual command in the background) you would need to select at least a number equal to the number of commands you want running at the same time (or 68 48 as the max).

Because the selection you make is stored in the file located at $HOME/.idevrc you either need to edit that file, or supply additional options to the idev command. If you want to permanently change the default, use the nano program, to edit the numerical value on the idev_tpn_noormal line. If you want to leave the default alone, and modify it just for the idev session you are currently creating, add one of the following options:

  1. -n 1 -N 1
  2. -n 68 48 -N 1

Note that in the above, it is the lowercase n that determines the number of tasks per node (1 and 68 48 respectively). The upper case N deals with how many different nodes (computers) you want access to. Programs can not interact across different nodes, so for idev sessions, you only ever want 1 "N"ode. There will be more information about this in Friday when working with the sbatch command.


...