Accessing the DIVMS Linux Machines

Background

• DIVMS is the Dividing of Mathematical Sciences (Computer Science, Mathematics, and Statistics and Actuarial Science).
• CSG is the Computer Support Group for the mathematical sciences departments
• CSG operates two Linux labs in MLH and one in 346 SH. In addition, there are several Linux servers that can be accessed by logging into linux.divms.uiowa.edu or linux.stat.uiowa.edu.
• All machines have shared home directories.
• The machines in 346 SH are intended for use by Statistics students and classes, so you should use one of these rather than machines in other labs or the servers.
• The lab machines in 346 SH are named l-lnx200.divms.uiowa.edu through l-lnx219.divms.uiowa.edu (also accessible as l-lnx200.stat.uiowa.edu through l-lnx219.stat.uiowa.edu.
• For longer running jobs, or when one of the other lab machines is not available, you can use statbigjobs.stat.uiowa.edu.
• For jobs requiring a large amount of RAM the research machine r-lnx400.stat.uiowa.edu is available; please ask for permission before using this.
• If you are a Statistics graduate student you should already have access to these systems. Othewise, to get access you should log in to the page at DIVMS Linux account page.

On Campus Remote Access

• The DIVMS lab machines are directly accessible from machines in the uiowa.edu domain using a secure shell (SSH) client.
• To log into the machine l-lnx207@divms.uiowa.edu from a terminal window on a Linux console on campus, use

  slogin YourUserID@l-lnx207.divms.uiowa.edu -X
  

  • The -X enables graphics forwarding. This means windows created on l-lnx207 will be displayed on your Linux console.
  • A similar approach works if you are using a Mac and have the X server installed.
• To log into the machine l-lnx207@divms.uiowa.edu from a Windows machine on campus, you can use an SSH client such as SecureCRT or SSH Secure Shell available from the ITS software download site.
  • This will not allow you to create graphics on l-lnx207 and have them displayed on your computer.
• You can also use the https://www.divms.uiowa.edu/clas_linux/help/fastx/index.htmlFastX web client from inside a browser, or download a desktop version from the browser login screen.

Off Campus Remote Access

• To log into the 346 SH machines from off campus you must first log into linux.divms.uiowa.edu and then into a particular workstation.
• If you use SSH you must either first establish a VPN connection or connect to port 40.
• If you are using the FastX client, the on and off campus procedure is identical.

Choosing a Workstation

• Small jobs can be run on any of the workstations in 346 SH.
• Larger jobs, such a s simulation that needs to run over night, should be run by logging into statbigjobs.stat.uiowa.edu.
• Large jobs should be run in background and should be ``niced'' to a value of 19; see the CSG help on process management for details.

Uploading Files

You have several options for uploading files:

• You can use scp, the command line secure copy program that comes with many SSH clients, if you have it available.
• The SSH Secure Shell distribution for Windows, available from the ITS software download site, includes a GUI client for file transfer.
• You can also use a secure FTP client; see the CSG help on file transfer from Windows.
• From on campus you can mount your DIVMS home directory as a network drive.
• You can use a USB device on the workstations in 346 SH (I assume this is not disabled but have not checked).
• You can avoid the issue by working on one of the 346 SH workstations, either on the console or remotely using SSH or the NoMachine NX client.