Hoffman2:Interactive Sessions

From Center for Cognitive Neuroscience
Revision as of 23:10, 12 April 2012 by Elau (talk | contribs)
Jump to navigation Jump to search

Back to all things Hoffman2

Interactive sessions on Hoffman2 let you have access to a computing node for up to 24 hours. This is ideal for:

  • running a intensive program like MATLAB (in fact that's how it works), WEKA, [[Hoffman2:R|R] or FSLView
  • debugging a script you will be submitting to the queue later
  • moving/tar'ing/untar'ing lots of files
  • any other computing or graphics intensive operations

since you aren't supposed to use the login nodes for such heavy lifting.


Basic Command

To get one, you need to use the qrsh command with the -l i flag.

For example

$ qrsh -l i

will try to get you an interactive node. That dash-elle flag followed by the "i" is specifying that you want an interactive resource.

Because you didn't specify a time limit this session will only last two hours after which you will be kicked off of the interactive node back to a login node.

And if all the interactive nodes are busy (there are only so many of them), then you will be told it was unable to secure one for you.


Longer Time

If you wanted to specify a a time limit for your interactive session (anything less than 24 hours), use the resource flag again and specify time in the HH:MM:SS format.

For example

$ qrsh -l i,time=4:00:00

will try securing an interactive node for four hours, but if they are all taken you will be kindly told you are out of luck.


Now!

If you absolutely need an interactive session now and can't take no for an answer, use a special flag -now no.

For example

$ qrsh -l i,time=4:00:00 -now no

will try securing an interactive node for four hours. But if all of the interactive nodes are used up, it will put you in a queue waiting for one until you get it.


External Links